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Effective Date: August 22, 2007
Mandatory Compliance Date: February 22, 2008
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TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
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Technical Standards Document
Number 116, Revision 0
Motor Vehicle Brake Fluids
As defined by section
12 of the Motor Vehicle Safety Act, a Technical Standards Document
(TSD) is a document that reproduces an enactment of a foreign government
(e.g. a Federal Motor Vehicle Safety Standard issued by the U.S. National
Highway Traffic Safety Administration). According to the Act, the Motor
Vehicle Safety Regulations may alter or override some provisions
contained in a TSD or specify additional requirements; consequently, it
is advisable to read a TSD in conjunction with the Act and its counterpart
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(Original signed by)
Director, Standards Research and Development
for the Minister of Transport,
Infrastructure and Communities
Ottawa, Ontario
Technical Standards Document
Number 116, Revision 0
MOTOR VEHICLE BRAKE FLUIDS
The text of this document is based on Federal Motor Vehicle Safety
Standard No. 116, Motor Vehicle Brake Fluids, as published
in the U.S. Code of Federal Regulations, Title 49, Part 571,
revised as of October 1, 2006.
S1. Scope
This Technical Standards Document (TSD) standard specifies requirements for fluids for use in hydraulic brake systems of motor
vehicles,
containers for these fluids, and labeling of the containers.
S2. Purpose
The purpose of this TSD standard is to reduce
failures in the hydraulic braking systems of motor vehicles which may occur
because of the manufacture or use of improper or contaminated fluid.
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S3. Application
[CONTENT DELETED] For applicability, see Schedule
III and subsection
116(1) of Schedule IV to the Motor Vehicle Safety Regulations.
S4. Definitions
Blister means a cavity or sac on the surface of a brake cup. (Ampoule)
Brake fluid means a liquid designed for use in a motor vehicle
hydraulic brake system in which it will contact elastomeric components
made of styrene and butadiene rubber (SBR), ethylene and propylene rubber
(EPR), polychloroprene (CR) brake hose inner tube stock, or natural rubber
(NR). (Liquide de frein)
Chipping means a condition in which small pieces are missing from the outer surface of a brake cup.
(Ébréchée)
Duplicate samples means two samples of brake fluid taken from a single packaged lot and tested simultaneously.
(Échantillons identiques)
Hydraulic system mineral oil means a mineral-oil-based fluid designed for use in motor vehicle hydraulic brake systems in which the fluid is not in contact with components made of SBR, EPR or NR.
(Huile minérale pour circuit hydraulique)
Packager means any person who fills containers with brake fluid that are subsequently distributed for retail sale.
(Emballeur)
Packaged lot is that quantity of brake fluid shipped by the manufacturer to the packager in a single container, or that quantity of brake fluid manufactured by a single plant run of 24 hours or less, through the same processing equipment and with no change in ingredients.
(Lot emballé)
Scuffing means a visible erosion of a portion of the outer surface of a brake cup.
(Éraflure)
A silicone base brake fluid (SBBF) is a brake fluid which consists
of not less than 70 percent by weight of a diorgano polysiloxane.
(Liquide de frein à base de silicone)
Sloughing means degradation of a brake cup as evidenced by the presence of carbon black loosely held on the brake cup surface such that a visible black streak is produced when the cup, with a 500 ± 10 gram deadweight on it, is drawn base down over a sheet of white bond paper placed on a firm flat surface.
(Encrassement)
Stickiness means a condition on the surface of a brake cup such
that fibers will be pulled from a wad of U.S.P. absorbent cotton when
it is drawn across the surface. (Gommage)
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S5. Requirements
This section specifies performance requirements for DOT 3, DOT 4, and
DOT 5 brake fluids; requirements for brake fluid certification;
and requirements for container sealing, labeling and color coding for
brake fluids and hydraulic system mineral oils. Where a range
of tolerances is specified, the brake fluid shall meet the requirements
at all points within the range.
S5.1 Brake fluid
When tested in accordance with S6, brake fluids shall meet the following
requirements:
S5.1.1 Equilibrium reflux boiling point (ERBP)
When brake fluid is tested according to S6.1, the ERBP shall not be less
than the following value for the grade indicated:
(a) DOT 3: 205°C (401°F),
(b) DOT 4: 230°C (446°F),
(c) DOT 5: 260°C (500°F).
S5.1.2 Wet ERxBP
When brake fluid is tested according to S6.2, the wet ERBP shall not
be less than the following value for the grade indicated:
(a) DOT 3: 140°C (284°F),
(b) DOT 4: 155°C (311°F),
(c) DOT 5: 1 180°C (356°F).
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S5.1.3 Kinematic viscosities
When brake fluid is tested according to S6.3, the kinematic viscosities in square millimeters per second at stated temperatures shall be neither less than 1.5
mm2/s at 100°C (212°F) nor more than the following maximum value for the grade indicated:
(a) DOT 3: 1,500 mm2/s at -40°C (-40°F),
(b) DOT 4: 1,800 mm2/s at -40°C (-40°F),
(c) DOT 5: 900 mm2/s at -40°C (-40°F).
S5.1.4 pH value
When brake fluid, except DOT 5 SBBF, is tested according to S6.4, the pH value shall not be less than 7.0 nor more than 11.5.
S5.1.5 Brake fluid stability
S5.1.5.1 High-temperature stability. When brake fluid
is tested according to S6.5.3, the ERBP shall not change by more than
3°C (5.4°F) plus 0.05°C (0.09°F) for each degree that the ERBP
of the fluid exceeds 225°C (437°F).
S5.1.5.2 Chemical stability. When brake fluid, except DOT 5 SBBF, is tested according to S6.5.4, the change in temperature of the refluxing fluid mixture shall not exceed 3.0°C (5.4°F) plus 0.05°C (0.09°F) for each degree that the ERBP of the fluid exceeds 225°C (437°F).
S5.1.6 Corrosion
When brake fluid is tested according to S6.6:
(a) The metal test strips shall not show mass weight changes exceeding the limits stated in Table I:
Table
I
Test Strip Material |
Maximum Permissible Mass Weight Change, mg/cm2 of surface |
Steel, tinned, cast iron |
0.2 |
Aluminium |
0.1 |
Brass, copper |
0.4 |
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(b) Excluding the area of contact [13 ± 1 mm (1/2 ± 1/32 inch) measured from the bolt hole end of the test strip], the metal test strips shall not show pitting or etching to an extent discernible without magnification;
(c) The water-wet brake fluid at the end of the test shall show no jelling at 23 ± 5°C (73.4 ± 9°F);
(d) No crystalline deposit shall form and adhere to either the glass jar walls or the surface of the metal strips;
(e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume;
(f) The pH value of water-wet brake fluid, except DOT 5 SBBF, at the end of the test shall not be less than 7.0 nor more than 11.5;
(g) The cups at the end of the test shall show no disintegration, as evidenced by blisters or sloughing;
(h) The hardness of the cup shall not decrease by more than 15 International Rubber Hardness Degrees
(IRHD); and
(i) The base diameter of the cups shall not increase by more than 1.4 mm (0.055 inch).
S5.1.7 Fluidity and appearance at low temperature
When brake fluid is tested according to S6.7, at the storage temperature and for the storage times given in Table II:
(a) The fluid shall show no sludging, sedimentation, crystallization, or stratification;
(b) Upon inversion of the sample bottle, the time required for the air bubble to travel to the top of the fluid shall not exceed the bubble flow times shown in Table II; and
(c) On warming to room temperature, the fluid shall resume the appearance and fluidity that it had before chilling.
Table II — Fluidity and Appearance at Low Temperature
Storage Temperature |
Storage Time (hours) |
Maximum Bubble Flow Time (seconds) |
-40 ± 2°C (-40
± 3.6°C) |
144 ± 4.0 |
10 |
-50 ± 2°C (-58
± 3.6°C) |
6 ± 0.2 |
35 |
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S5.1.8 Evaporation
[Reserved]
S5.1.9 Water tolerance
(a) At low temperature. When brake fluid is tested according to S6.9.3(a):
(1) The fluid shall show no sludging, sedimentation, crystallization, or
stratification;
(2) Upon inversion of the centrifuge tube, the air bubble shall travel to the top of the fluid in not more than 10 seconds;
(3) If cloudiness has developed, the wet fluid shall regain its original clarity and fluidity when warmed to room temperature; and
(b) At 60°C (140°F). When brake fluid is tested according to S6.9.3(b):
(1) The fluid shall show no stratification; and
(2) Sedimentation shall not exceed 0.15 percent by volume after centrifuging.
S5.1.10 Compatibility
(a) At low temperature. When brake fluid is tested according to S6.10.3(a), the test specimen shall show no sludging, sedimentation, or crystallization. In addition, fluids, except DOT 5 SBBF, shall show no stratification.
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(b) At 60°C (140°F). When brake fluid is tested according to S6.10.3(b):
(1) Sedimentation shall not exceed 0.05 percent by volume after centrifuging;
and
(2) Fluids, except DOT 5 SBBF, shall show no stratification.
S5.1.11 Resistance to oxidation
When brake fluid is tested according to S6.11:
(a) The metal test strips outside the areas in contact with the tinfoil
shall not show pitting or etching to an extent discernible without magnification;
(b) No more than a trace of gum shall be deposited on the test strips
outside the areas in contact with the tinfoil;
(c) The aluminum strips shall not change in mass weight
by more than 0.05 mg/cm2; and
(d) The cast iron strips shall not change in mass
weight by more than 0.3 mg/cm2.
S5.1.12 Effects on cups
When brake cups are subjected to brake fluid in accordance with S6.12:
(a) The increase in the diameter of the base of the cups shall be not
less than 0.15 mm (0.006 inch) or more than 1.40 mm (0.055 inch);
(b) The decrease in hardness of the cups shall be not more than 10
IRHD at 70°C (158°F) or more than 15 IRHD at 120°C (248°F), and there
shall be no increase in hardness of the cups; and
(c) The cups shall show no disintegration as evidenced by stickiness,
blisters, or sloughing.
S5.1.13 Stroking properties
When brake fluid is tested according to S6.13:
(a) Metal parts of the test system shall show no pitting or etching
to an extent discernible without magnification;
(b) The change in diameter of any cylinder or piston shall not exceed
0.13 mm (0.005 inch);
(c) The average decrease in hardness of seven of the eight cups tested
(six wheel cylinder and one master cylinder primary) shall not exceed
15 IRHD. Not more than one of the seven cups shall have a decrease in
hardness greater than 17 IRHD;
(d) None of the eight cups shall be in an unsatisfactory operating
condition as evidenced by stickiness, scuffing, blisters, cracking,
chipping, or other change in shape from its original appearance;
(e) None of the eight cups shall show an increase in base diameter
greater than 0.90 mm (0.035 inch);
(f) The average lip diameter set of the eight cups shall not be greater
than 65 percent;
(g) During any period of 24,000 strokes, the volume loss of fluid shall
not exceed 36 mL;
(h) The cylinder pistons shall not freeze or function improperly throughout
the test;
(i) The total loss of fluid during the 100 strokes at the end of the
test shall not exceed 36 mL;
(j) The fluid at the end of the test shall show no formation of gels;
(k) At the end of the test, the amount of sediment shall not exceed
1.5 percent by volume; and
(l) Brake cylinders shall be free of deposits that are abrasive or
that cannot be removed when rubbed moderately with a nonabrasive cloth
wetted with ethanol.
S5.1.14 Fluid color
Brake fluid and hydraulic system mineral oil shall be of the color indicated:
DOT 3, DOT 4, and DOT 5.1 non-SBBF — colorless to amber.
DOT 5 SBBF — purple.
Hydraulic system mineral oil — green.
S5.2 Packaging and labeling requirements for motor vehicle brake fluids
[CONTENT DELETED]
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S5.3 Motor vehicle requirement
[CONTENT DELETED] For applicability, see
Schedule III and subsection
116(1) of Schedule IV to the Motor Vehicle Safety Regulations.
S6. Test procedures
S6.1 Equilibrium reflux boiling point
Determine the ERBP of a brake fluid by running duplicate samples
according to the following procedure and averaging the results.
S6.1.1 Summary of procedure
Sixty milliliters (mL) of brake fluid are boiled under specified equilibrium
conditions (reflux) at atmospheric pressure in a 100-mL flask. The average
temperature of the boiling fluid at the end of the reflux period, corrected
for variations in barometric pressure if necessary, is the ERBP.
S6.1.2 Apparatus (See Figure 1)
The test apparatus shall consist of:
(a) Flask. (See Figure 2) A 100-mL round-bottom, short-neck, heat-resistant
glass flask having a neck with a 19/38 standard-taper, female ground-glass
joint, and a side-entering tube, with an outside diameter of 10 mm,
which centers the thermometer bulb in the flask 6.5 mm from the bottom;
(b) Condenser. A water-cooled, reflux, glass-tube type, condenser having
a jacket 200 mm in length, the bottom end of which has a 19/38 standard-taper,
drip-tip, male ground-glass joint;
(c) Boiling stones. Three clean, unused silicon carbide grains (approximately
2 mm (0.08 inch) in diameter, grit No. 8);
(d) Thermometers. Standardized calibrated partial immersion (76 mm),
solid stem, thermometers conforming to the requirements for an ASTM
2C or 2F, and an ASTM 3C or 3F thermometer; and
(e) Heat source. Variable autotransformer-controlled heating mantle
designed to fit the flask, or an electric heater with rheostat heat
control.
S6.1.3 Preparation of apparatus
(a) Thoroughly clean and dry all glassware.
(b) Insert thermometer through the side tube until the tip of the bulb
is 6.5 mm (1/4 inch) from the bottom center of the flask. Seal with
a short piece of natural rubber, EPDM, SBR, or butyl tubing.
(c) Place 60 ± 1 mL of brake fluid and the silicon carbide grains into
the flask.
(d) Attach the flask to the condenser. When using a heating mantle,
place the mantle under the flask and support it with a ring-clamp and
laboratory-type stand, holding the entire assembly in place by a clamp.
When using a rheostat-controlled heater, center a standard porcelain
or hard asbestos refractory, having a diameter opening 32 to 38 mm,
over the heating element and mount the flask so that direct heat is
applied only through the opening in the refractory. Place the assembly
in an area free from drafts or other types of sudden temperature changes.
Connect the cooling water inlet and outlet tubes to the condenser. Turn
on the cooling water. The water supply temperature shall not exceed
28°C (82.4°F) and the temperature rise through the condenser shall not
exceed 2°C (3.6°F).
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Figure 1 — Boiling Point Test Apparatus
Figure 2 — Detail of 100 mL Short Neck-Flash
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S6.1.4 Procedure
Apply heat to the flask so that within 10 ± 2 minutes the fluid is refluxing in excess of 1 drop per second. The reflux rate shall not exceed 5 drops per second at any time. Immediately adjust the heating rate to obtain an equilibrium reflux rate of 1 to 2 drops per second over the next 5 ± 2 minutes. Maintain this rate for an additional 2 minutes, taking four temperature readings at 30-second intervals. Record the average of these as the observed ERBP. If no reflux is evident when the fluid temperature reaches 260°C (500°F), discontinue heating and report ERBP as in excess of 260°C (500°F).
S6.1.5 Calculation
(a) Thermometer inaccuracy. Correct the observed ERBP by applying any correction factor obtained in standardizing the thermometer.
(b) Variation from standard barometric pressure. Apply the factor shown in Table III to calculate the barometric pressure correction to the
ERBP.
Table III — Correction for Barometric Pressure
Observed ERBP Corrected
for Thermometer Inaccuracy |
Correction per 1 mm
Difference in Pressure, ºC* |
100°C to 190ºC |
0.039 |
Over 190ºC |
0.04 |
* To be added in case barometric pressure is below 760 mm; to be subtracted
in case barometric pressure is above 760 mm.
(c) If the two corrected observed ERBP's agree within 2°C [4°C for
brake fluids having an ERBP over 230°C (446°F)], average the duplicate
runs as the ERBP; otherwise, repeat the entire test, averaging the four
corrected observed values to determine the original ERBP.
S6.2 Wet ERBP
Determine the wet ERBP of a brake fluid by running duplicate samples according to the following procedure.
S6.2.1 Summary of procedure
A 350 mL sample of the brake fluid is humidified under controlled conditions;
350 mL of SAE triethylene glycol monomethyl ether, brake fluid grade,
referee material (TEGME) as described in Appendix E of SAE Standard J1703
Nov. 83, Motor Vehicle Brake Fluid, November 1983, is used to
establish the end point for humidification. After humidification, the
water content and ERBP of the brake fluid are determined.
S6.2.2 Apparatus for humidification (See Figure 3)
Test apparatus shall consist of:
(a) Glass jars. Four SAE RM-49 corrosion test jars or equivalent screwtop, straight-sided, round glass jars each having a capacity of about 475 mL and approximate inner dimensions of 100 mm in height by 75 mm in diameter, with matching lids having new, clean inserts providing water-vapor-proof seals;
(b) Desiccators and covers. Two bowl-form glass desiccators, 250-mm inside diameter, having matching tubulated covers fitted with No. 8 rubber stoppers; and
(c) Desiccator plates. Two 230-mm diameter, perforated porcelain desiccator plates, without feet, glazed on one side.
S6.2.3 Reagents and materials
(a) Distilled water, see S7.1.
(b) SAE TEGME referee material.
S6.2.4 Preparation of apparatus
Lubricate the ground-glass joint of the desiccator. Pour 450 ± 10 mL of distilled water into each desiccator and insert perforated porcelain desiccator plates. Place the desiccators in an oven with temperature controlled at 50 ± 1°C (122 ± 1.8°F) throughout the humidification procedure.
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Figure 3 — Humidification Apparatus
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S6.2.5 Procedure
Pour 350 ± 5 mL of brake fluid into an open corrosion test jar. Prepare in the same manner a duplicate test fluid sample and two duplicate specimens of the SAE TEGME referee material (350 ± 5 mL of TEGME in each jar). The water content of the SAE TEGME fluid is adjusted to 0.50 ± 0.05 percent by weight at the start of the test in accordance with S7.2. Place one sample each of the test brake fluid and the prepared TEGME sample into the same desiccator. Repeat for the second sample of test brake fluid and TEGME in a second desiccator. Place the desiccators in the 50°C (122°F) controlled oven and replace desiccator covers. At intervals during oven humidification, remove the rubber stoppers in the tops of desiccators. Using a long needled hypodermic syringe, take a sample of not more than 2 mL from each TEGME sample and determine its water content. Remove no more than 10 mL of fluid from each SAE TEGME sample during the humidification procedure. When the water content of the SAE fluid reaches 3.70 ± 0.05 percent by weight (average of the duplicates), remove the two test fluid specimens from their desiccators and promptly cap each jar tightly. Allow the sealed jars to cool for 60 to 90 minutes at 23 ± 5°C (73.4 ± 9°F). Measure the water content of the test fluid specimens in accordance with S7.2 and determine their ERBP's in accordance with S6.1. If the two ERBPs agree within 4°C (8°F), average them to determine the wet ERBP; otherwise repeat and average the four individual ERBPs as the wet ERBP of the brake fluid.
S6.3 Kinematic viscosity
Determine the kinematic viscosity of a brake fluid in mm2/s by the following procedure. Run duplicate samples at each of the specified temperatures, making two timed runs on each sample.
S6.3.1 Summary of the procedure
The time is measured for a fixed volume of the brake fluid to flow through a calibrated glass capillary viscometer under an accurately reproducible head and at a closely controlled temperature. The kinematic viscosity is then calculated from the measured flow time and the calibration constant of the viscometer.
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(a) Viscometers. Calibrated glass capillary-type viscometers, ASTM D2515-66,
Standard Specification for Kinematic Glass Viscometers,1
measuring viscosity within the precision limits of S6.3.7 S6.4.7.
Use suspended level viscometers for viscosity measurements at low temperatures.
Use Cannon-Fenske Routine or other modified Ostwald viscometers at ambient
temperatures and above.
(b) Viscometer holders and frames. Mount a viscometer in the constant-temperature
bath so that the mounting tube is held within 1° of the vertical.
(c) Viscometer bath. A transparent liquid bath of sufficient depth such
that at no time during the measurement will any portion of the sample
in the viscometer be less than 2 cm below the surface or less than 2 cm
above the bottom. The bath shall be cylindrical in shape, with turbulent
agitation sufficient to meet the temperature control requirements. For
measurements within 15 to 100°C (60 to 212°F), the temperature of the
bath medium shall not vary by more than 0.01°C (0.02°F) over the length
of the viscometers, or between the positions of the viscometers, or at
the locations of the thermometers. Outside this range, the variation shall
not exceed 0.03°C (0.05°F).
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(d) Thermometers. Liquid-in-Glass Kinematic Viscosity Test Thermometers
covering the range of test temperatures indicated in Table IV and conforming
to ASTM E1-68, Specifications for ASTM Thermometers,1
and in the IP requirements for IP Standard Thermometers. Standardize before
use (see S6.3.3(b)). Use two standardized thermometers in the bath.
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Table IV — Kinematic Viscosity Thermometers
Temperature
Range |
For Tests
at |
Subdivisions |
Thermometer
No. |
°C |
°F |
°C |
°F |
°C |
°F |
ASTM |
IP |
-55.3|
to
-52.5 |
-67.5
to
-62.5 |
-55 |
-67 |
0.05 |
0.1 |
74 F |
69 F or C |
-41.4
to
-38.6 |
-42.5
to
-37.5 |
-40 |
-40 |
0.05 |
0.1 |
73 F |
68 F or C |
98.6
to
101.4 |
207.5
to
212.5 |
100 |
212 |
0.05 |
0.1 |
30 F |
32 F or C |
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(e) Timing device. Stop watch or other timing device graduated in
divisions representing not more than 0.2 second, with an accuracy of at
least ± 0.05 percent when tested over intervals of 15 minutes. Electrical
timing devices may be used when the current frequency is controlled to
an accuracy of 0.01 percent or better.
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(a) Viscometers. Use viscometers calibrated in accordance with Appendix
1 of ASTM D445-65, Viscosity of Transparent and Opaque Liquids (Kinematic
and Dynamic Viscosities).1 The calibration
constant, C, is dependent upon the gravitational acceleration at
the place of calibration. This must, therefore, be supplied by the standardization
laboratory together with the instrument constant. Where the acceleration
of gravity, g, in the two locations differs by more than 0.1 percent,
correct the calibration constant as follows:
where the subscripts 1 and 2 indicate, respectively, the standardization
laboratory and the testing laboratory.
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(b) Thermometers. Check liquid-in-glass thermometers to the nearest 0.01°C
(0.02°F) by direct comparison with a standardized thermometer. Kinematic
Viscosity Test Thermometers shall be standardized at "total immersion."
The ice point of standardized thermometers shall be determined before
use and the official corrections shall be adjusted to conform to the changes
in ice points. (See ASTM E77-66, Verification and Calibration of Liquid-in-Glass
Thermometers.)1
(c) Timers. Time signals are broadcast by the National Institute
of Standards and Technology National Bureau of Standards,
Station WWV, Fort Collins, Colorado, Washington, DC
at 2.5, 5, 10, 15, 20, 25, 30, and 35 Mc/sec (MHz). Time signals are also
broadcast by Station CHU from Ottawa, Canada, at 3.330, 7.335, and 14.670
Mc/sec, and Station MSF at Rugby, United Kingdom, at 2.5, 5,
and 10 Mc/sec.
S6.3.4 Procedure
(a) Set and maintain the bath at the appropriate test temperature (see S5.1.3) within the limits specified in S6.3.2(c). Apply the necessary corrections, if any, to all thermometer readings.
(b) Select a clean, dry, calibrated viscometer giving a flow time not less than its specified minimum, or 200 seconds, whichever is the greater.
(c) Charge the viscometer in the manner used when the instrument was calibrated. Do not filter or dry the brake fluid, but protect it from contamination by dirt and moisture during filling and measurements.
(1) Charge the suspended level viscometer by tilting about 30° from the vertical and pouring sufficient brake fluid through the fill tube into the lower reservoir so that, when the viscometer is returned to vertical position, the meniscus is between the fill marks. For measurements below 0°C (32°F), before placing the filled viscometer into the constant temperature bath, draw the sample into the working capillary and timing bulb and insert small rubber stoppers to suspend the fluid in this position, to prevent accumulation of water condensate on the walls of the critical portions of the viscometer. Alternatively, fit loosely packed drying tubes into the open ends of the viscometer to prevent water condensation, but do not restrict the flow of the sample under test by the pressures created in the instrument.
(2) If a Cannon-Fenske Routine viscometer is used, charge by inverting and immersing the smaller arm into the brake fluid and applying vacuum to the larger arm. Fill the tube to the upper timing mark, and return the viscometer to an upright position.
(d) Mount the viscometer in the bath in a true vertical position (see S6.3.2(b)).
(e) The viscometer shall remain in the bath until it reaches the test temperature.
(f) At temperatures below 0°C (32°F), conduct an untimed preliminary run by allowing the brake fluid to drain through the capillary into the lower reservoir after the test temperature has been established.
(g) Adjust the head level of the brake fluid to a position in the capillary arm about 5 mm above the first timing mark.
(h) With brake fluid flowing freely, measure to within 0.2 second the time required for the meniscus to pass from the first timing mark to the second. If this flow time is less than the minimum specified for the viscometer, or 200 seconds, whichever is greater, repeat using a viscometer with a capillary of smaller diameter.
(i) Repeat S6.3.4 (g) and (h). If the two timed runs do not agree within 0.2 percent, reject and repeat using a fresh sample of brake fluid.
S6.3.5 Cleaning the viscometer
(a) Periodically clean the instrument with chromic acid to remove organic deposits. Rinse thoroughly with distilled water and acetone, and dry with clean dry air.
(b) Between successive samples, rinse the viscometer with ethanol (isopropanol when testing DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered dry air through the viscometer until the last trace of solvent is removed.
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S6.3.6 Calculation
(a) The following viscometers have a fixed volume charged
at ambient temperature, and as a consequence, C varies with test
temperature: Cannon-Fenske Routine, Pinkevitch, Cannon-Manning Semi-Micro,
and Cannon Fenske Opaque. To calculate C at test temperatures
other than the calibration temperature for these viscometers, see ASTM
D2515-66, Kinematic Glass Viscometers,1
or follow instructions given on the manufacturer's certificate of calibration.
(b) Average the four timed runs on the duplicate samples
to determine the kinematic viscosities.
S6.3.7 Precision (at 95 percent confidence level)
(a) Repeatability. If results on duplicate samples by
the same operator differ by more than 1 percent of their mean, repeat
the tests.
S6.4 pH value
Determine the pH value of a brake fluid by running one sample
according to the following procedure.
S6.4.1 Summary of the procedure
Brake fluid is diluted with an equal volume of an ethanol-water
solution. The pH of the resultant mixture is measured with a prescribed
pH meter assembly at 23°C (73.4°F).
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S6.4.2 Apparatus
The pH assembly consists of the pH meter, glass electrode, and calomel
electrode, as specified in Appendices A1.1, A1.2, and A1.3 of ASTM D1121-67,
Standard Method of Test for Reserve Alkalinity of Engine Antifreezes
and Antirusts.1 The glass electrode
is a full range type (pH 0-14), with low sodium error.
S6.4.3 Reagents
Reagent grade chemicals conforming to the specifications of the Committee
on Analytical Reagents of the American Chemical Society.
(a) Distilled water. Distilled water (S7.1) shall be boiled for about
15 minutes to remove carbon dioxide and protected with a soda-lime tube
or its equivalent while cooling and in storage. (Take precautions to
prevent contamination by the materials used for protection against carbon
dioxide.) The pH of the boiled distilled water shall be between 6.2
and 7.2 at 25°C (77°F).
(b) Standard buffer solutions. Prepare buffer solutions for calibrating
the pH meter and electrode pair from salts sold specifically for use,
either singly or in combination, as pH standards. Dry salts for 1 hour
at 110°C (230°F) before use except for borax which shall be used as
the decahydrate. Store solutions with pH less than 9.5 in bottles of
chemically resistant glass or polyethylene. Store the alkaline phosphate
solution in a glass bottle coated inside with paraffin. Do not use a
standard with an age exceeding three months.
(1) Potassium hydrogen phthalate buffer solution [0.05 M, pH = 4.01
at 25°C (77°F)]. Dissolve 10.21 g of potassium hydrogen phthalate
(KHC8H4O4) in distilled water. Dilute
to 1 liter.
(2) Neutral phosphate buffer solution [0.025 M with respect to each
phosphate salt, pH = 6.86 at 25°C (77°F)]. Dissolve 3.40 g of potassium
dihydrogen phosphate (KH2PO4) and 3.55 g of
anhydrous disodium hydrogen phosphate (Na2HPO4)
in distilled water.
(3) Borax buffer solution [0.01 M, pH = 9.18 at 25°C (77°F)]. Dissolve
3.81 g of disodium tetraborate decahydrate (Na2B4O7·10
H2O) in distilled water, and dilute to 1 liter. Stopper
the bottle except when actually in use.
(4) Alkaline phosphate buffer solution [0.01 M trisodium phosphate,
pH = 11.72 at 25°C (77°F)]. Dissolve 1.42 g of anhydrous disodium
hydrogen phosphate (Na2HPO4) in 100 mL of a
0.1 M carbonate-free solution of sodium hydroxide. Dilute to 1 liter
with distilled water.
(5) Potassium chloride electrolyte. Prepare a saturated solution
of potassium chloride (KCl) in distilled water.
(c) Ethanol-water mixture. To 80 parts by volume of ethanol (S7.3)
add 20 parts by volume of distilled water. Adjust the pH of the mixture
to 7 ± 0.1 using 0.1 N sodium hydroxide (NaOH) solution. If more than
4 mL of NaOH solution per liter of mixture is required for neutralization,
discard the mixture.
S6.4.4 Preparation of electrode system
(a) Maintenance of electrodes. Clean the glass electrode before using
by immersing in cold chromic-acid cleaning solution. Drain the calomel
electrode and fill with KCl electrolyte, keeping level above that of
the mixture at all times. When not in use, immerse the lower halves
of the electrodes in distilled water, and do not immerse in the mixture
for any appreciable period of time between determinations.
(b) Preparation of electrodes. Condition new glass electrodes and those
that have been stored dry as recommended by the manufacturer. Before
and after using, wipe the glass electrode thoroughly with a clean cloth,
or a soft absorbent tissue, and rinse with distilled water. Before each
pH determination, soak the prepared electrode in distilled water for
at least 2 minutes. Immediately before use, remove any excess water
from the tips of the electrode.
S6.4.5 Standardization of the pH assembly and testing of the
electrodes
(a) Immediately before use, standardize the pH assembly with a standard
buffer solution. Then use a second standard buffer solution to check
the linearity of the response of the electrodes at different pH values,
and to detect a faulty glass electrode or incorrect temperature compensation.
The two buffer solutions bracket the anticipated pH value of the test
brake fluid.
(b) Allow instrument to warm up and adjust according to the manufacturer's
instructions. Immerse the tips of the electrodes in a standard buffer
solution and allow the temperature of the buffer solution and the electrodes
to equalize. Set the temperature knob at the temperature of the buffer
solution. Adjust the standardization of asymmetry potential control
until the meter registers a scale reading, in pH units, equal to the
known pH of the standardizing buffer solution.
(c) Rinse the electrodes with distilled water and remove excess water
from the tips. Immerse the electrodes in a second standard buffer solution.
The reading of the meter shall agree with the known pH of the second
standard buffer solution within ± 0.05 unit without changing the setting
of the standardization of asymmetry potential control.
(d) A faulty electrode is indicated by failure to obtain a correct
value for the pH of the second standard buffer solution after the meter
has been standardized with the first.
S6.4.6 Procedure
To 50 ± 1 mL of the test brake fluid, add 50 ± 1 mL of the ethanol-water
mixture (S6.4.3(c)) and mix thoroughly. Immerse the electrodes in the
mixture. Allow the system to come to equilibrium, readjust the temperature
compensation if necessary, and take the pH reading.
S6.5 Fluid stability
Evaluate the heat and chemical stability of a brake fluid by the following
procedure, running duplicate samples for each test and averaging the results.
S6.5.1 Summary of the procedure
The degradation of the brake fluid at elevated temperature, alone or
in a mixture with a reference fluid, is evaluated by determining the change
in boiling point after a period of heating under reflux conditions.
S6.5.2 Apparatus
Use the apparatus and preparation specified in S6.1.2 and S6.1.3.
S6.5.3 High temperature stability
S6.5.3.1 Procedure
(a) Heat a new 60 ± 1 mL sample of the brake fluid to 185 ± 2°C (365
± 3.6°F). Hold at this temperature for 120 ± 5 minutes. Bring to a reflux
rate in excess of 1 drop per second within 5 minutes. The reflux rate
should not exceed 5 drops per second at any time. Over the next 5 ±
2 minutes, adjust the heating rate to obtain an equilibrium reflux rate
of 1 to 2 drops per second. Maintain this rate for an additional 2 minutes,
taking four temperature readings at 30-second intervals. Average these
as the observed ERBP. If no reflux is evident when the fluid temperature
reaches 260°C (500°F), discontinue heating and report ERBP as in excess
of 260°C (500°F).
S6.5.3.2 Calculation. Correct the observed ERBP for thermometer
and barometric pressure factors according to S6.1.5 (a) and (b). Average
the corrected ERBP's of the duplicate samples. The difference between
this average and the original ERBP obtained in S6.1 is the change in ERBP
of the fluid.
S6.5.4 Chemical stability
S6.5.4.1 Materials. SAE RM-66-04 Compatibility Fluid as described
in Appendix B of SAE Standard J1703 JAN 1995, Motor Vehicle Brake
Fluid. [SENTENCE DELETED]
S6.5.4.2 Procedure
(a) Mix 30 ± 1 mL of the brake fluid with 30 ± 1 mL of SAE RM-66-04
Compatibility Fluid in a boiling point flask (S6.1.2(a)). Determine
the initial ERBP of the mixture by applying heat to the flask so that
the fluid is refluxing in 10 ± 2 minutes at a rate in excess of 1 drop
per second, but not more than 5 drops per second. Note the maximum fluid
temperature observed during the first minute after the fluid begins
refluxing at a rate in excess of 1 drop per second. Over the next 15
± 1 minutes, adjust and maintain the reflux rate at 1 to 2 drops per
second. Maintain this rate for an additional 2 minutes, recording the
average value of four temperature readings taken at 30-second intervals
as the final ERBP.
(b) Thermometer and barometric corrections are not required.
S6.5.4.3 Calculation. The difference between the initial ERBP
and the final average temperature is the change in temperature of the
refluxing mixture. Average the results of the duplicates to the nearest
0.5°C (1.0°F).
S6.6 Corrosion
Evaluate the corrosiveness of a brake fluid by running duplicate samples
according to the following procedure.
S6.6.1 Summary of the procedure. Six specified metal corrosion
test strips are polished, cleaned, and weighed, then assembled as described.
Assembly is placed on a standard wheel cylinder cup in a corrosion test
jar, immersed in the water-wet brake fluid, capped, and placed in an oven
at 100°C (212°F) for 120 hours. Upon removal and cooling, the strips,
fluid, and cups are examined and tested.
S6.6.2 Equipment
(a) Balance. An analytical balance having a minimum capacity of 50
g and capable of weighing to the nearest 0.1 mg.
(b) Desiccators. Desiccators containing silica gel or other suitable
desiccant.
(c) Oven. Gravity convection oven capable of maintaining the desired
set point within 2°C (3.6°F).
(d) Micrometer. A machinist's micrometer 25 to 50 mm (1 to 2 inches)
capacity, or an optical comparator, capable of measuring the diameter
of the SBR wheel cylinder (WC) cups to the nearest 0.02 mm (0.001 inch).
S6.6.3 Materials
(a) Corrosion test strips. Two sets of strips from each of the metals
listed in Appendix C of SAE Standard J1703b, Motor Vehicle Brake
Fluid, July 1970. Each strip shall be approximately 8 cm long,
1.3 cm wide, not more than 0.6 cm thick, and have a surface area of 25
± 5 square cm and a hole 4 to 5 mm (0.16 to 0.20 inch) in diameter on
the centerline about 6 mm from one end. The hole shall be clean and free
from burrs. Tinned iron strips shall be unused. Other strips, if used,
shall not be employed if they cannot be polished to a high finish.
(b) SBR cups. Two unused standard SAE SBR wheel cylinder (WC) cups, as
specified in S7.6.
(c) Corrosion test jars and lids. Two screw-top, straight-sided round
glass jars, each having a capacity of approximately 475 mL and inner dimensions
of approximately 100 mm in height and 75 mm in diameter, and a tinned
steel lid (no insert or organic coating) vented with a hole 0.8 ± 0.1
mm (0.031 ± 0.004 inch) in diameter (No. 68 drill).
(d) Machine screws and nuts. Clean, rust and oil-free, uncoated mild
steel round or fillister head machine screws, size 6 or 8-32 UNC-Class
2A, five-eighths or three-fourths inch long (or equivalent metric sizes),
and matching uncoated nuts.
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(e) Supplies for polishing strips. Waterproof silicon carbide paper,
grit No. 320 and grit No. 1200; lint-free polishing cloth.
(f) Distilled water as specified in S7.1.
(g) Ethanol as specified in S7.3.
(h) Isopropanol as specified in S7.7.
S6.6.4 Preparation
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(a) Corrosion test strips. Except for the tinned iron strips, abrade corrosion test strips on all surface areas with 320A silicon carbide paper wet with ethanol (isopropanol when testing DOT 5 SBBF fluids) until all surface scratches, cuts, and pits visible to an observer having corrected visual acuity of 20/40 (Snellen ratio) at a distance of 300 mm (11.8 inches) are removed. Use a new piece of paper for each different type of metal. Except for the tinned iron strips, further abrade the test strips on all surface areas with 1200 silicon carbide paper wet with ethanol (isopropanol when testing DOT 5 SBBF fluids), again using a new piece of paper for each different type of metal.
Wash all strips,
including the tinned iron and the assembly hardware, with ethanol (isopropanol
when testing DOT 5 SBBF fluids); dry the strips and assembly hardware
with a clean lint-free cloth or use filtered compressed air and place
the strips and hardware in a desiccator containing silica gel or other
suitable desiccant and maintained at 23 ± 5°C (73.4 ± 9°F), for at least
1 hour. Handle the strips with forceps after polishing. Weigh and record
the mass weight of each strip to the nearest
0.1 mg. Assemble the strips on a clean dry machine screw, with matching
plain nut, in the order of tinned iron, steel, aluminum, cast iron,
brass, and copper. Bend the strips, other than the cast iron, so that
there is a separation of 3 ± 0.5 mm (1/8 ± 1/64 inch) between adjacent
strips for a distance of about 5 cm (2 inches) from the free end of
the strips. (See Figure 4.) Tighten the screw on each test strip assembly
so that the strips are in electrolytic contact and can be lifted by
either of the outer strips (tinned iron or copper) without any of the
strips moving relative to the others when held horizontally. Immerse
the strip assemblies in 90 percent ethyl alcohol. Dry with dried filtered
compressed air, then desiccate at least 1 hour before use.
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Figure 4 — Corrosion Strip Assembly
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(b) SBR WC cups. Measure the base diameters of the two standard SBR
cups, using an optical comparator or micrometer, to the nearest 0.02
mm (0.001 inch) along the centerline of the SAE and rubber-type identifications
and at right angles to this centerline. Take the measurements at least
0.4 mm (0.015 inch) above the bottom edge and parallel to the base of
the cup. Discard any cup if the two measured diameters differ by more
than 0.08 mm (0.003 inch). Average the two readings on each cup. Determine
the hardness of the cups according to S7.4.
S6.6.5 Procedure
Rinse the cups in ethanol (isopropanol when testing DOT 5 SBBF fluids)
for not more than 30 seconds and wipe dry with a clean lint-free cloth.
Place one cup with lip edge facing up in each jar. Insert a metal strip
assembly inside each cup with the fastened end down and the free end extending
upward. (See Figure 5.) When testing brake fluids, except DOT 5 SBBF,
mix 760 mL of brake fluid with 40 mL of distilled water. When testing
DOT 5 SBBF's, humidify 800 mL of brake fluid in accordance with S6.2,
eliminating determination of the ERBP. Using this water-wet mixture, cover
each strip assembly to a minimum depth of 10 mm above the tops of the
strips. Tighten the lids and place the jars for 120 ± 2 hours in an oven
maintained at 100 ± 2°C (212 ± 3.6°F). Allow the jars to cool at 23 ±
5°C (73.4 ± 9°F) for 60 to 90 minutes. Immediately remove the strips from
the jars using forceps, agitating the strip assembly in the fluid to remove
loose adhering sediment. Examine the test strips and jars for adhering
crystalline deposits. Disassemble the metal strips, and remove adhering
fluid by flushing with water; clean each strip by wiping with a clean
cloth wetted with ethanol (isopropanol when testing DOT 5 fluids). Examine
the strips for evidence of corrosion and pitting. Disregard staining or
discoloration. Place the strips in a desiccator containing silica gel
or other suitable desiccant, maintained at 23 ± 5°C (73.4 ± 9°F), for
at least 1 hour. Weigh each strip to the nearest 0.1 mg. Determine the
change in mass weight of each metal strip. Average
the results for the two strips of each type of metal. Immediately following
the cooling period, remove the cups from the jars with forceps. Remove
loose adhering sediment by agitation of the cups in the mixture. Rinse
the cups in ethanol (isopropanol when testing DOT 5 fluids) and air-dry.
Examine the cups for evidence of sloughing, blisters, and other forms
of disintegration. Measure the base diameter and hardness of each cup
within 15 minutes after removal from the mixture. Examine the mixture
for gelling. Agitate the mixture to suspend and uniformly disperse sediment.
From each jar, transfer a 100 mL portion of the mixture to an ASTM cone-shaped
centrifuge tube. Determine the percent sediment after centrifuging as
described in S7.5. Measure the pH value of the corrosion test fluid according
to S6.4.6. Measure the pH value of the test mixture according to S6.4.6.
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Figure 5 — Corrosion Test Apparatus
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S6.6.6 Calculation
(a) Measure the area of each type of test strip to the nearest square centimeter. Divide the average change in mass for each type by the area of that type.
(b) Note other data and evaluations indicating compliance with S5.1.6. In the event of a marginal pass on inspection by attributes, or of a failure in one of the duplicates, run another set of duplicate samples. Both repeat samples shall meet all requirements of S5.1.6.
S6.7 Fluidity and appearance at low temperatures
Determine the fluidity and appearance of a sample of brake fluid at each of two selected temperatures by the following procedure.
S6.7.1 Summary of procedure
Brake fluid is chilled to expected minimum exposure temperatures and observed for clarity, gellation, sediment, separation of components, excessive viscosity, or
thixotropy.
S6.7.2 Apparatus
(a) Oil sample bottles. Two clear, flint glass 118-mL (4-ounce) bottles made especially for sampling oil and other liquids, with a capacity of approximately 125 mL, an outside diameter of 37 ± 0.05 mm, and an overall height of 165 ± 2.5 mm.
(b) Cold chamber. An air bath cold chamber capable of maintaining storage temperatures down to -55°C (-67°F) with an accuracy of ± 2°C (3.6°F).
(c) Timing device. A timing device in accordance with S6.3.2(e).
S6.7.3 Procedure
(a) Place 100 ± 1 mL of brake fluid at room temperature in an oil sample bottle. Stopper the bottle with an unused cork and place in the cold chamber at the higher storage temperature specified in Table II (S5.1.7(c)). After 144 ± 4 hours, remove the bottle from the chamber, quickly wipe it with a clean, lint-free cloth saturated with ethanol (isopropanol when testing DOT 5
fluids) or acetone. Examine the fluid for evidence of sludging, sedimentation, crystallization, or stratification. Invert the bottle and determine the number of seconds required for the air bubble to travel to the top of the fluid. Let sample warm to room temperature and examine.
(b) Repeat S6.7.3(a), substituting the lower cold chamber temperature specified in Table II and a storage period of 6 hours ± 12 minutes.
Note: Test specimens from either storage temperature may be used for the other only after warming up to room temperature.
S6.8 Evaporation
[Reserved]
S6.9 Water tolerance
Evaluate the water tolerance characteristics of a brake fluid by running one test specimen according to the following procedure.
S6.9.1 Summary of the procedure
Brake fluid, except DOT 5 SBBF, is diluted with 3.5 percent water (DOT 5 SBBF is humidified), then stored at -40°C (-40°F) for 120 hours. The cold, water-wet fluid is first examined for clarity, stratification, and sedimentation, then placed in an oven at 60°C (140°F) for 24 hours. On removal, it is again examined for stratification, and the volume percent of sediment determined by centrifuging.
S6.9.2 Apparatus
(a) Centrifuge tube. See S7.5.1(a).
(b) Centrifuge. See S7.5.1(b).
(c) Cold chamber. See S6.7.2(b).
(d) Oven. Gravity or forced convection oven.
(e) Timing device. See S6.3.2(e).
S6.9.3 Procedure
(a) At low temperature. Humidify 100 ± 1 mL of DOT 5 SBBF brake fluid in accordance with S6.2, eliminating determination of the ERBP. When testing brake fluids, except DOT 5 SBBF, mix 3.5 ± 0.1 mL of distilled water with 100 ± 1 mL of the brake fluid; pour into a centrifuge tube. Stopper the tube with a clean cork and place in the cold chamber maintained at -40 ± 2°C (-40 ± 3.6°F). After 120 hours ± 2 hours, remove the tube, quickly wipe with clean lint-free cloth saturated with ethanol
or acetone, and examine the fluid for evidence of sludging, sedimentation, crystallization, or stratification. Invert the tube and determine the number of seconds required for the air bubble to travel to the top of the fluid. (The air bubble is considered to have reached the top of the fluid when the top of the bubble reaches the 2-mL graduation of the centrifuge tube.) If the wet fluid has become cloudy, warm to 23 ± 5°C (73.4 ± 9°F) and note appearance and fluidity.
(b) At 60°C (140°F). Place tube and brake fluid from S6.9.3(a) in an oven maintained at 60 ± 2°C (140 ± 3.6°F) for 24 ± 2 hours. Remove the tube and immediately examine the contents for evidence of stratification. Determine the percent sediment by centrifuging as described in S7.5.
S6.10 Compatibility
The compatibility of a brake fluid with other brake fluids shall be evaluated by running one test sample according to the following procedure.
S6.10.1 Summary of the procedure
Brake fluid is mixed with an equal volume of SAE RM-66-04 Compatibility Fluid, then tested in the same way as for water tolerance (S6.9), except that the bubble flow time is not measured. This test is an indication of the compatibility of the test fluid with other motor vehicle brake fluids at both high and low temperatures.
S6.10.2 Apparatus and materials
(a) Centrifuge tube. See S7.5.1(a).
(b) Centrifuge. See S7.5.1(b).
(c) Cold Chamber. See S6.7.2(b).
(d) Oven. See S6.9.2(d).
(e) SAE RM-66-04 Compatibility Fluid. As described in Appendix B of SAE
Standard J1703 JAN 1995, Motor Vehicle Brake Fluid. [SENTENCE
DELETED]
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S6.10.3 Procedure
(a) At low temperature. Mix 50 ± 0.5 mL of brake fluid with 50 ± 0.5 mL of SAE RM-66-04 Compatibility Fluid. Pour this mixture into a centrifuge tube and stopper with a clean dry cork. Place tube in the cold chamber maintained at -40 ± 2°C (-40 ± 4°F). After 24 ± 2 hours, remove tube, quickly wipe with a clean lint-free cloth saturated with ethanol
(isopropanol when testing DOT 5 fluids) or acetone. Examine the test specimen for evidence of
sludging, sedimentation, or crystallization. Test fluids, except DOT 5 SBBF, shall be examined for stratification.
(b) At 60°C (140°F). Place tube and test fluid from
S6.10.3(a) for 24 ± 2 hours in an oven maintained at 60 ± 2°C
(140 ± 3.6°F). Remove the tube and immediately examine the contents of
the test mixtures, except DOT 5 SBBFs, for evidence of stratification.
Determine percent sediment by centrifuging as described in S7.5.
S6.11 Resistance to oxidation
The stability of a brake fluid under oxidative conditions shall be evaluated by running duplicate samples according to the following procedure.
S6.11.1 Summary of procedure
Brake fluids, except DOT 5 SBBF fluids, are activated with a mixture of approximately 0.2 percent benzoyl peroxide and 5 percent water. DOT 5 SBBF fluid is humidified in accordance with S6.2, eliminating determination of the ERBP, and then approximately 0.2 percent benzoyl peroxide is added. A corrosion test strip assembly consisting of cast iron and an aluminum strip separated by tinfoil squares at each end is then rested on a piece of SBR WC cup positioned so that the test strip is half immersed in the fluid and oven aged at 70°C (158°F) for 168 hours. At the end of this period, the metal strips are examined for pitting, etching, and loss of mass.
S6.11.2 Equipment
(a) Balance. See S6.6.2(a).
(b) Desiccators. See S6.6.2(b).
(c) Oven. See S6.6.2(c).
(d) Three glass test tubes approximately 22 mm outside diameter by 175 mm in length.
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S6.11.3 Reagents and materials
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(a) Benzoyl peroxide, reagent grade, 96 percent. (Benzoyl peroxide that
is brownish, or dusty, or has less than 90 percent purity, must be discarded.)
Reagent strength may be evaluated by ASTM E298-68, Standard Methods
for Assay of Organic Peroxides.1
(b) Corrosion test strips. Two sets of cast iron and aluminum metal test
strips as described in Appendix C of SAE Standard J1703b.
(c) Tinfoil. Four unused pieces of tinfoil approximately 12 mm (1/2 inch)
square and between 0.02 and 0.06 mm (0.0008 and 0.0024 inch) in thickness.
The foil shall be at least 99.9 percent tin and contain not more than
0.025 percent lead.
(d) SBR cups. Two unused, approximately one-eighth sections of a standard
SAE SBR WC cup (as described in S7.6).
(e) Machine screws and nuts. Two clean oil-free, No. 6 or 8-32 x 3/8
- or 1/2-inch long (or equivalent metric size), round or fillister head,
uncoated mild steel machine screws, with matching plain nuts.
S6.11.4 Preparation
(a) Corrosion test strips. Prepare two sets of aluminum and cast iron
test strips according to S6.6.4(a), except for assembly. Weigh each
strip to the nearest 0.1 mg and assemble a strip of each metal on a
machine screw, separating the strips at each end with a piece of tinfoil.
Tighten the nut enough to hold both pieces of foil firmly in place.
(b) Test mixture. Place 30 ± 1 mL of the brake fluid under test in
a 22 by 175 mm test tube. For all fluids except DOT 5 SBBF fluids, add
0.060 ± 0.002 grams of benzoyl peroxide and 1.50 ± 0.05 mL of distilled
water. For DOT 5 SBBF fluids, use test fluid humidified in accordance
with S6.2, and add only the benzoyl peroxide. Stopper the tube loosely
with a clean dry cork, shake, and place in an oven for 2 hours at 70
± 2°C (158 ± 3.6°F). Shake every 15 minutes to effect solution of the
peroxide, but do not wet cork. Remove the tube from the oven and allow
to cool to 23 ± 5°C (73.4 ± 9°F). Begin testing according to S6.11.5
not later than 24 hours after removal of tube from oven.
S6.11.5 Procedure
Place a one-eighth SBR cup section in the bottom of each tube. Add 10
mL of prepared test mixture to each test tube. Place a metal-strip assembly
in each, the end of the strips without the screw resting on the rubber,
and the solution covering about one-half the length of the strips. Stopper
the tubes with clean dry corks and store upright for 70 ± 2 hours at 23
± 5°C (73.4 ± 9°F). Loosen the corks and place the tubes for 168 ± 2 hours
in an oven maintained at 70 ± 2°C (158 ± 3.6°F). Afterwards remove and
disassemble strips. Examine the strips and note any gum deposits. Wipe
the strips with a clean cloth wet with ethanol (isopropanol when testing
DOT 5 fluids) and note any pitting, etching, or roughening of surface,
disregarding stain or discoloration. Place the strips in a desiccator
over silica gel or other suitable desiccant at 23 ± 5°C (73.4 ± 9°F) for
at least 1 hour. Again weigh each strip to the nearest 0.1 mg.
S6.11.6 Calculation
Determine corrosion loss by dividing the change in mass of each metal
strip by the total surface area of each strip measured in square millimeters
(mm2) to the nearest square millimeter. Average the results
for the two strips of each type of metal, rounding to the nearest 0.05
mg per 100 mm2. If only one of the duplicates fails for any
reason, run a second set of duplicate samples. Both repeat samples shall
meet all requirements of S5.1.11.
6.12 Effect on SBR cups
The effects of a brake fluid in swelling, softening, and otherwise affecting
standard SBR WC cups shall be evaluated by the following procedure.
S6.12.1 Summary of the procedure
Four standard SAE SBR WC cups are measured and their hardness determined.
The cups, two to a jar, are immersed in the test brake fluid. One jar
is heated for 70 hours at 70°C (158°F), and the other for 70 hours at
120°C (248°F). Afterwards, the cups are washed, examined for disintegration,
remeasured, and their hardness redetermined.
S6.12.2 Equipment and supplies
(a) Oven. See S6.6.2(c).
(b) Glass jars and lids. Two screw-top, straight-sided round glass
jars, each having a capacity of approximately 250 mL and inner dimensions
of approximately 125 mm in height and 50 mm in diameter, and a tinned
steel lid (no insert or organic coating).
(c) SBR cups. See S7.6.
S6.12.3 Preparation
Measure the base diameters of the SBR cups as described in S6.6.4(b),
and the hardness of each as described in S7.4.
S6.12.4 Procedure
Wash the cups in 90 percent ethanol (isopropanol when testing DOT 5 fluids)
(see S7.3) for not longer than 30 seconds and quickly dry with a clean,
lint-free cloth. Using forceps, place two cups into each of the two jars;
add 75 mL of brake fluid to each jar and cap tightly. Place one jar in
an oven held at 70 ± 2°C (158 ± 3.6°F) for 70 ± 2 hours. Place the other
jar in an oven held at 120 ± 2°C (248 ± 3.6°F) for 70 ± 2 hours. Allow
each jar to cool for 60 to 90 minutes at 23 ± 5°C (73.4 ± 9°F). Remove
cups, wash with ethanol (isopropanol when testing DOT 5 fluids) for not
longer than 30 seconds, and quickly dry. Examine the cups for disintegration
as evidenced by stickiness, blisters, or sloughing. Measure the base diameter
and hardness of each cup within 15 minutes after removal from the fluid.
S6.12.5 Calculation
(a) Calculate the change in base diameter for each cup. If the two
values, at each temperature, do not differ by more than 0.10 mm (0.004
inch), average them to the nearest 0.02 mm (0.001 inch). If the two
values differ by more than 0.10 mm, repeat the test at the appropriate
temperature and average the four values as the change in base diameter.
(b) Calculate the change in hardness for each cup. The average of the
two values for each pair is the change in hardness.
(c) Note disintegration as evidenced by stickiness, blisters, or sloughing.
S6.13 Stroking properties
Evaluate the lubricating properties, component compatibility, resistance
to leakage, and related qualities of a brake fluid by running one sample
according to the following procedures.
S6.13.1 Summary of the procedure
Brake fluid is stroked under controlled conditions at an elevated temperature
in a simulated motor vehicle hydraulic braking system consisting of three
slave wheel cylinders and an actuating master cylinder connected by steel
tubing. Referee standard parts are used. All parts are carefully cleaned,
examined, and certain measurements made immediately prior to assembly
for test. During the test, temperature, rate of pressure rise, maximum
pressure, and rate of stroking are specified and controlled. The system
is examined periodically during stroking to assure that excessive leakage
of fluid is not occurring. Afterwards, the system is torn down. Metal
parts and SBR cups are examined and remeasured. The brake fluid and any
resultant sludge and debris are collected, examined, and tested.
S6.13.2 Apparatus and equipment
Either the drum and shoe type of stroking apparatus (see Figure 1 of
SAE Standard J1703b) except using only three sets of drum and shoe assemblies,
or the stroking fixture type apparatus as shown in Figure 2 of SAE J1703Nov83,
with the components arranged as shown in Figure 1 of SAE J1703Nov83. The
following components are required.
(a) Brake assemblies. With the drum and shoe apparatus: three drum
and shoe assembly units (SAE RM-29a) consisting of three forward brake
shoes and three reverse brake shoes with linings and three front wheel
brake drum assemblies with assembly component parts. With stroking fixture
type apparatus: three fixture units including appropriate adapter mounting
plates to hold brake wheel cylinder assemblies.
(b) Braking pressure actuation mechanism. An actuating mechanism for
applying a force to the master cylinder pushrod without side thrust.
The amount of force applied by the actuating mechanism shall be adjustable
and capable of applying sufficient thrust to the master cylinder to
create a pressure of at least 6,895 kPa (1,000 psi) in the simulated
brake system. A hydraulic gage or pressure recorder, having a range
of at least 0 to 6,895 kPa (0 to 1,000 psi), shall be installed between
the master cylinder and the brake assemblies and shall be provided with
a shutoff valve and with a bleeding valve for removing air from the
connecting tubing. The actuating mechanism shall be designed to permit
adjustable stroking rates of approximately 1,000 strokes per hour. Use
a mechanical or electrical counter to record the total number of strokes.
(c) Heated air bath cabinet. An insulated cabinet or oven having sufficient
capacity to house the three mounted brake assemblies or stroking fixture
assemblies, master cylinder, and necessary connections. A thermostatically
controlled heating system is required to maintain a temperature of 70
± 5°C (158 ± 9°F) or 120 ± 5°C (248 ± 9°F). Heaters shall be shielded
to prevent direct radiation to wheel or master cylinder.
(d) Master cylinder (MC) assembly (SAE RM-15a). One cast-iron housing
hydraulic brake system cylinder having a diameter of approximately 28
mm (1 1/8 inch) and fitted for a filler cap and standpipe (see S6.13.2(e)).
The MC piston shall be made from SAE CA 360 copperbase alloy (half hard).
A new MC assembly is required for each test.
(e) Filler cap and standpipe. MC filler cap provided with a glass or
uncoated steel standpipe. Standpipe must provide adequate volume for
thermal expansion, yet permit measurement and adjustment of the fluid
level in the system to ± 3 mL. Cap and standpipe may be cleaned and
reused.
(f) Wheel cylinder (WC) assemblies (SAE RM-14a). Three unused cast-iron
housing straight bore hydraulic brake WC assemblies having diameters
of approximately 28 mm (1 1/8 inch) for each test. Pistons shall be
made from unanodized SAE AA 2024 aluminum alloy.
(g) Micrometer. Same as S6.6.2(d).
S6.13.3 Materials
(a) Standard SBR brake cups. Six standard SAE SBR wheel cylinder test
cups, one primary MC test cup, and one secondary MC test cup, all as
described in S7.6, for each test.
(b) Steel tubing. Double-wall steel tubing meeting SAE specification
J527. A complete replacement of tubing is essential when visual inspection
indicates any corrosion or deposits on inner surface of tubing. Tubing
from master cylinder to one wheel cylinder shall be replaced for each
test (minimum length 0.9 m). Uniformity in tubing size is required between
master cylinder and wheel cylinder. The standard master cylinder has
two outlets for tubing, both of which must be used.
S6.13.4 Preparation of test apparatus
(a) Wheel cylinder assemblies. Use unused wheel cylinder assemblies.
Disassemble cylinders and discard cups. Clean all metal parts with ethanol
(isopropanol when testing DOT 5 fluids). Inspect the working surfaces
of all metal parts for scoring, galling, or pitting and cylinder bore
roughness, and discard all defective parts. Remove any stains on cylinder
walls with crocus cloth and ethanol (isopropanol when testing DOT 5
fluids). If stains cannot be removed, discard the cylinder. Measure
the internal diameter of each cylinder at a location approximately 19
mm (0.75 inch) from each end of the cylinder bore, taking measurements
in line with the hydraulic inlet opening and at right angles to this
centerline. Discard the cylinder if any of these four readings exceeds
the maximum or minimum limits of 28.66 to 28.60 mm (1.128 to 1.126 inch).
Measure the outside diameter of each piston at two points approximately
90° apart. Discard any piston if either reading exceeds the maximum
or minimum limits of 28.55 to 28.52 mm (1.124 to 1.123 inch). Select
parts to insure that the clearance between each piston and mating cylinder
is within 0.08 to 0.13 mm (0.003 to 0.005 inch). Use unused SBR cups.
To remove dirt and debris, rinse the cups in 90 percent ethyl alcohol
for not more than 30 seconds and wipe dry with a clean lint-free cloth.
Discard any cups showing defects such as cuts, molding flaws, or blisters.
Measure the lip and base diameters of all cups with an optical comparator
or micrometer to the nearest 0.02 mm (0.001 inch) along the centerline
of the SAE and rubber-type identifications and at right angles to this
centerline. Determine base diameter measurements at least 0.4 mm (0.015
inch) above the bottom edge and parallel to the base of the cup. Discard
any cup if the two measured lip or base diameters differ by more than
0.08 mm (0.003 inch). Average the lip and base diameters of each cup.
Determine the hardness of all cups according to S7.4. Dip the rubber
and metal parts of wheel cylinders, except housing and rubber boots,
in the fluid to be tested and install them in accordance with the manufacturer's
instructions. Manually stroke the cylinders to insure that they operate
easily. Install cylinders in the simulated brake system.
(b) Master cylinder assembly. Use an unused master cylinder and unused
standard SBR primary and secondary MC cups which have been inspected,
measured, and cleaned in the manner specified in S6.13.4(a), omitting
hardness of the secondary MC cup. However, prior to determining the
lip and base diameters of the secondary cup, dip the cup in test brake
fluid, assemble on the MC piston, and maintain the assembly in a vertical
position at 23 ± 5°C (73.4 ± 9°F) for at least 12 hours. Inspect the
relief and supply ports of the master cylinder; discard the cylinder
if ports have burrs or wire edges. Measure the internal diameter of
the cylinder at two locations [approximately midway between the relief
and supply ports and approximately 19 mm (0.75 inch) beyond the relief
port toward the bottom or discharge end of the bore], taking measurements
at each location on the vertical and horizontal centerline of the bore.
Discard the cylinder if any reading exceeds the maximum or minimum limits
of 28.65 to 28.57 mm (1.128 to 1.125 inch). Measure the outside diameter
of each end of the master cylinder piston at two points approximately
90° apart. Discard the piston if any of these four readings exceed the
maximum or minimum limits of 28.55 to 28.52 mm (1.124 to 1.123 inch).
Dip the rubber and metal parts of the master cylinder, except the housing
and push rod-boot assembly, in the brake fluid and install in accordance
with manufacturer's instructions. Manually stroke the master cylinder
to insure that it operates easily. Install the master cylinder in the
simulated brake system.
(c) Assembly and adjustment of test apparatus
(1) When using a shoe and drum type apparatus, adjust the brake shoe
toe clearances to 1.0 ± 0.1 mm (0.040 ± 0.004 inch). Fill the system
with brake fluid, bleeding all wheel cylinders and the pressure gage
to remove entrapped air. Operate the actuator manually to apply a
pressure greater than the required operating pressure and inspect
the system for leaks. Adjust the actuator and/or pressure relief valve
to obtain a pressure of 6,895 ± 345 kPa (1,000 ± 50 psi). A smooth
pressure stroke pattern is required when using a shoe and drum type
apparatus. The pressure is relatively low during the first part of
the stroke and then builds up smoothly to the maximum stroking pressure
at the end of the stroke, to permit the primary cup to pass the compensating
hole at a relatively low pressure. Using stroking fixtures, adjust
the actuator and/or pressure relief valve to obtain a pressure of
6,895 ± 345 kPa (1,000 ± 50 psi).
(2) Adjust the stroking rate to 1,000 ± 100 strokes per hour. Record
the fluid level in the master cylinder standpipe.
S6.13.5 Procedure
Operate the system for 16,000 ± 1,000 cycles at 23 ± 5°C (73.4 ± 9°F).
Repair any leakage, readjust the brake shoe clearances, and add fluid
to the master cylinder standpipe to bring to the level originally recorded,
if necessary. Start the test again and raise the temperature of the cabinet
within 6 ± 2 hours to 120 ± 5°C (248 ± 9°F). During the test, observe
operation of wheel cylinders for improper functioning and record the amount
of fluid required to replenish any loss at intervals of 24,000 strokes.
Stop the test at the end of 85,000 total recorded strokes. This total
shall include the number of strokes during operation at 23 ± 5°C (73.4
± 9°F) and the number of strokes required to bring the system to the operating
temperature. Allow equipment to cool to room temperature. Examine the
wheel cylinders for leakage. Stroke the assembly an additional 100 strokes,
examine wheel cylinders for leakage, and record volume loss of fluid.
Within 16 hours after stopping the test, remove the master and wheel cylinders
from the system, retaining the fluid in the cylinders by immediately capping
or plugging the ports. Disassemble the cylinders, collecting the fluid
from the master cylinder and wheel cylinders in a glass jar. When collecting
the stroked fluid, remove all residue which has deposited on rubber and
metal internal parts by rinsing and agitating such parts in the stroked
fluid and using a soft brush to assure that all loose adhering sediment
is collected. Clean SBR cups in ethanol (isopropanol when testing DOT
5 fluids) and dry. Inspect the cups for stickiness, scuffing, blistering,
cracking, chipping, and change in shape from original appearance. Within
1 hour after disassembly, measure the lip and base diameters of each cylinder
cup by the procedures specified in S6.13.4(a) and (b) with the exception
that lip or base diameters of cups may now differ by more than 0.08 mm
(0.003 inch). Determine the hardness of each cup according to S7.4. Note
any sludge or gel present in the test fluid. Within 1 hour after draining
the cylinders, agitate the fluid in a glass jar to suspend and uniformly
disperse sediment and transfer a 100 mL portion of this fluid to a centrifuge
tube and determine percent sediment as described in S7.5. Allow the tube
and fluid to stand for 24 hours, recentrifuge, and record any additional
sediment recovered. Inspect cylinder parts, note any gumming or any pitting
on pistons and cylinder walls. Disregard staining or discoloration. Rub
any deposits adhering to cylinder walls with a clean soft cloth wetted
with ethanol (isopropanol when testing DOT 5 fluids) to determine abrasiveness
and removability. Clean cylinder parts in ethanol (isopropanol when testing
DOT 5 fluids) and dry. Measure and record diameters of pistons and cylinders
according to S6.13.4(a) and (b). Repeat the test if mechanical failure
occurs that may affect the evaluation of the brake fluid.
S6.13.6 Calculation
(a) Calculate the changes in diameters of cylinders and pistons (see
S5.1.13(b)).
(b) Calculate the average decrease in hardness of the seven cups tested,
as well as the individual values (see S5.1.13(c)).
(c) Calculate the increases in base diameters of the eight cups (see
S5.1.13(e)).
(d) Calculate the lip diameter interference set for each of the eight
cups by the following formula and average the eight values (see S5.1.13(f)).
where:
D1 = Original lip diameter
D2 = Final lip diameter
D3 = Original cylinder bore diameter
S6.14 Container information
[CONTENT DELETED]
S7. Auxiliary test methods and reagent standards
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S7.1 Distilled water
Nonreferee reagent water as specified in ASTM D1193-70, Standard
Specifications for Reagent Water,1
or water of equal purity.
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S7.2 Water content of motor vehicle brake fluids
Use analytical methods based on ASTM D1123-59, Standard Method of
Test for Water in Concentrated Engine Antifreezes by the Iodine Reagent
Method,1 for determining the water
content of brake fluids, or other methods of analysis yielding comparable
results. To be acceptable for use, such other method must measure the
mass weight of water added to samples of the
SAE RM-66-04 and TEGME Compatibility Fluids within ± 15 percent of the
water added for additions up to 0.8 percent by weight, and within ± 5
percent of the water added for additions greater than 0.8 percent by weight.
The SAE RM-66-04 Compatibility Fluid used to prepare the samples must
have an original ERBP of not less than 205°C (401°F) when tested in accordance
with S6.1. The SAE TEGME fluid used to prepare the samples must have an
original ERBP of not less than 240°C (464°F) when tested in accordance
with S6.1.
S7.3 Ethanol
95 percent (190 proof) ethyl alcohol, USP or ACS, or Formula 3-A Specially Denatured Alcohol of the same concentration (as specified
in the U.S. Code of Federal Regulations, Title 27, Part 21, Section 35 at 27 CFR
21.35). For pretest washings of equipment, use approximately 90 percent ethyl alcohol, obtained by adding 5 parts of distilled water to 95 parts of ethanol.
S7.4 Measuring the hardness of SBR brake cups
Hardness measurements on SBR wheel cylinder cups and master cylinder primary cups shall be made by using the following apparatus and the following procedure.
S7.4.1 Apparatus
(a) Anvil. A rubber anvil having a flat circular top 20 ± 1 mm (13/16 ± 1/16 inch) in diameter, a thickness of at least 9 mm (3/8 inch), and a hardness within 5 IRHDs of the SBR test cup.
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(b) Hardness tester. A hardness tester meeting the requirements for the
standard instrument as described in ASTM D1415-68, Standard Method
of Test for International Hardness of Vulcanized Natural and Synthetic
Rubbers,1 and graduated directly
in IRHD units.
S7.4.2 Procedure
Make hardness measurements at 23 ± 2°C (73.4 ± 4°F). Equilibrate the
tester and anvils at this temperature prior to use. Center brake cups
lip side down on an anvil of appropriate hardness. Following the manufacturer's
operating instructions for the hardness tester, make one measurement
at each of four points 6 mm from the center of the cup and spaced 90°
apart. Average the four values and round off to the nearest IRHD.
S7.5 Sediment by centrifuging
The amount of sediment in the test fluid shall be determined by the following
procedure.
S7.5.1 Apparatus
(a) Centrifuge tubes. Cone-shaped centrifuge tubes conforming to the
dimensions given in Figure 6 and made of thoroughly annealed glass.
The graduations shall be numbered as shown in Figure 6 and shall be
clear and distinct. Scale-error tolerances and smallest graduations
between various calibration marks are given in Table V and apply to
calibrations made with air-free water at 20°C (68°F).
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Figure 6 — ASTM 8-Inch Centrifuge Tube
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Table V — Calibration Tolerances for 8-Inch Centrifuge Tube
Range, mL |
Subdivision, mL |
Volume
tolerance, mL |
0 to 0.1 |
0.05 |
± 0.02 |
Above 0.1 to 0.3 |
0.05 |
± 0.03 |
Above 0.3 to 0.5 |
0.05 |
± 0.05 |
Above 0.5 to 1 |
0.10 |
± 0.05 |
Above 1 to 2 |
0.10 |
± 0.10 |
Above 2 to 3 |
0.20 |
± 0.10 |
Above 3 to 5 |
0.5 |
± 0.20 |
Above 5 to 10 |
1 |
± 0.50 |
Above 10 to 25 |
5 |
± 1.00 |
Above 25 to 100 |
25 |
± 1.00 |
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b) Centrifuge. A centrifuge capable of whirling two or more filled
centrifuge tubes at a speed which can be controlled to give a relative
centrifugal force (r.c.f.) between 600 and 700 at the tip of the tubes.
The revolving head, trunnion rings, and trunnion cups, including the
rubber cushion, shall withstand the maximum centrifugal force capable
of being delivered by the power source. The trunnion cups and cushions
shall firmly support the tubes when the centrifuge is in motion. Calculate
the speed of the rotating head using this equation:
where:
r.c.f. = Relative centrifugal force, and
d = Diameter of swing, in millimeters, measured between tips of opposing
tubes when in rotating position.
Table VI shows the relationship between diameter of swing, relative
centrifugal force (r.c.f.), and revolutions per minute.
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Table
VI — Rotation Speeds for Centrifuges of Various Diameters
Diameter of swing,
in millimetersa |
r.p.m. at
600 r.c.f. |
r.p.m. at
700 r.c.f. |
483 |
1490 |
1610 |
508 |
1450 |
1570 |
533 |
1420 |
1530 |
559 |
1390 |
1500 |
a Measured in millimeters
between tips of opposite tubes when in rotating position.
S7.5.2 Procedure
Balance the corked centrifuge tubes with their respective trunnion
cups in pairs by mass weight on a scale, according
to the centrifuge manufacturer's instructions, and place them on opposite
sides of the centrifuge head. Use a dummy assembly when one sample is
tested. Then whirl them for 10 minutes at a rate sufficient to produce
a r.c.f. between 600 and 700 at the tips of the whirling tubes. Repeat
until the volume of sediment in each tube remains constant for three
consecutive readings.
S7.5.3 Calculation
Read the volume of the solid sediment at the bottom of the centrifuge
tube and report the percent sediment by volume. Where replicate determinations
are specified, report the average value.
S7.6 Standard styrene-butadiene rubber (SBR)
brake cups
SBR brake cups for testing motor vehicle brake fluids shall be manufactured
using the following formulation:
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Formulation of Rubber Compound
Ingredients |
Parts by mass weight |
SBR type 1503a |
100 |
Oil furnace black (NBS 378) |
40 |
Zinc oxide (NBS 370) |
5 |
Sulfur (NBS 371) |
0.25 |
Stearic Acid (NBS 372) |
1 |
n-tertiary butyl-2-benzothiazole
sulfenamide (NBS 384) |
1 |
Symmetrical dibetanaphthyl-p-phenylenediamine |
1.5 |
Dicumyl peroxide (40 percent on precipitated CaCO3)b |
4.5 |
Total |
153.25 |
a Philprene 1503 has been found suitable.
b Use only within 90 days of manufacture and store at temperature below 27°C (80°F).
NOTE: The ingredients
labeled (NBS) must have properties identical with those supplied by the
U.S. National Institute Bureau of Standards
and Technology.
Compounding, vulcanization, physical properties, size of the finished cups, and other details shall be as specified in Appendix B of SAE J1703b. The cups shall be used in testing brake fluids either within 6 months from date of manufacture, when stored at room temperature below 30°C (86°F), or within 36 months from date of manufacture, when stored at temperatures below -15°C (+5°F). After removal of cups from refrigeration, they shall be conditioned base down on a flat surface for at least 12 hours at room temperature in order to allow cups to reach their true configuration before measurement.
S7.7 Isopropanol
ACS (American Chemical Society) or reagent grade.
ENDNOTE:
1 Please see subsection
116(2) of the Motor Vehicle Safety Regulations (MVSR)
for an alternative requirement.
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