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Effective Date: August 22, 2007
Mandatory Compliance Date: February 22, 2008
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Technical Standards Document
Number 106, Revision 0
Brake Hoses
(Ce
document est aussi disponible en franηais.)
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
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The HTML version is provided for information purposes only.
(Original signed by)
Director, Standards Research and Development
for the Minister of Transport,
Infrastructure and Communities
Ottawa, Ontario
Technical Standards Document
Number 106, Revision 0
BRAKE HOSES
The text of this document is based on Federal Motor Vehicle
Safety Standard No. 106, Brake Hoses, as published in the U.S.
Code of Federal Regulations, Title 49, Part 571, revised as
of October 1, 2004.
S1. Scope
This Technical Standards Document (TSD) standard
specifies labeling and performance requirements for motor vehicle brake
hose, brake hose assemblies, and brake hose end fittings.
S2. Purpose
The purpose of this TSD standard is to reduce
deaths and injuries occurring as a result of brake system failure from
pressure or vacuum loss due to hose or hose assembly rupture.
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S3. Application
[CONTENT DELETED] For applicability, see
Schedule III and subsections
106(1) and (2) of Schedule IV to the Motor Vehicle Safety Regulations.
S4. Definitions
Armor means protective material installed on a brake hose to increase
the resistance of the hose or hose assembly to abrasion or impact damage.
(Armure)
Brake hose means a flexible conduit, other than a vacuum tubing
connector, manufactured for use in a brake system to transmit or contain
the fluid pressure or vacuum used to apply force to a vehicle's brakes.
For a hose, a dimensional description such as "1/4-inch hose" refers to
the nominal inside diameter. For tubing, a dimensional description such
as "1/4-in tubing" refers to the nominal outside diameter. (Boyau
de frein)
Brake hose assembly means a brake hose, with or without armor,
equipped with end fittings for use in a brake system, but does not include
an air or vacuum assembly prepared by the owner or operator of a used
vehicle, by his employee, or by a repair facility, for installation in
that used vehicle. (Ensemble de boyau de frein)
Brake hose end fitting means a coupler, other than a clamp, designed
for attachment to the end of a brake hose. (Raccord d'extrιmitι de
boyau de frein)
Free length means the linear measurement of hose exposed between
the end fittings of a hose assembly in a straight position. (Longueur
libre)
Permanently attached end fitting means an end fitting that is
attached by deformation of the fitting about the hose by crimping or swaging,
or an end fitting that is attached by the use of a sacrificial sleeve
or ferrule that requires replacement each time a hose assembly is rebuilt.
(Raccord d'extrιmitι de boyau fixι en permanence)
Rupture means any failure that results in the separation of a
brake hose from its end fitting or in leakage. (Rupture)
Vacuum tubing connector means a flexible conduit of vacuum that
(i) connects metal tubing to metal tubing in a brake system, (ii) is attached
without end fittings, and (iii) when installed, has an unsupported length
less than the total length of those portions that cover the metal tubing.
(Raccord de tuyau à vide)
S5. Requirements Hydraulic brake hose, brake
hose assemblies, and brake hose end fittings
S5.1 Construction
(a) Each hydraulic brake hose assembly shall have permanently attached
brake hose end fittings which are attached by deformation of the fitting
about the hose by crimping or swaging.
(b) [CONTENT DELETED]
S5.2 Labeling
S5.2.1 [CONTENT DELETED]
S5.2.2 [CONTENT DELETED]
S5.2.3 [CONTENT DELETED]
S5.2.4 [CONTENT DELETED]
S5.2.4.1 At least one end fitting of a hydraulic brake hose assembly
shall be etched, stamped or embossed with a designation at least 1.6
mm (one-sixteenth of an inch) high that identifies the manufacturer
of the hose assembly and is filed in accordance with S5.2.4(b).
S5.3 Test requirements
A hydraulic brake hose assembly or appropriate part thereof shall be
capable of meeting any of the requirements set forth under this heading,
when tested under the conditions of S11 and the applicable procedures
of S6. However, a particular hose assembly or appropriate part thereof
need not meet further requirements after having been subjected to and
having met the constriction requirement (S5.3.1) and any one of the requirements
specified in S5.3.2 through S5.3.11.
S5.3.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a hydraulic
brake hose assembly shall be not less than 64 percent of the nominal inside
diameter of the brake hose.
S5.3.2 Expansion and burst strength. The maximum expansion of
a hydraulic brake hose assembly at 6 895 kPa (1,000 psi) and
10 342 kPa (1,500 psi) shall not exceed the values specified in Table
I (S6.1). The hydraulic brake hose assembly shall then withstand water
pressure of 27 579 kPa (4,000 psi) for 2 minutes without rupture,
and shall not rupture at less than 34 474 kPa (5,000 psi) (S6.2).
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Table
I Maximum Expansion of Free Length of
Brake Hose, mL/m (cc/ft.)
Hydraulic
Brake Hose, Inside Diameter |
Test
Pressure |
6
895 kPa (1,000 psi) |
10
342 kPa (1,500 psi) |
Regular
Expansion Hose |
Low
Expansion Hose |
Regular
Expansion Hose |
Low
Expansion Hose |
1/8
inch or 3 mm or less |
2.17
(0.66) |
1.08
(0.33) |
2.59
(0.79) |
1.38
(0.42) |
3/16
inch or 4 to 5 mm |
2.82
(0.86) |
1.80
(0.55) |
3.35
(1.02) |
2.36
(0.72) |
1/4
inch or 6 mm or more |
3.41
(1.04) |
2.69
(0.82) |
4.27
(1.30) |
3.84
(1.17) |
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S5.3.3 Whip resistance. A hydraulic
brake hose assembly shall not rupture when run continuously on a whip
test flexing machine for 35 hours (S6.3).
S5.3.4 Tensile strength. A hydraulic brake hose assembly shall
withstand a pull of 1 446 N (325 pounds) without separation of
the hose from its end fittings (S6.4).
S5.3.5 Water absorption and burst strength. A hydraulic brake
hose assembly, after immersion in water for 70 hours (S6.5), shall withstand
water pressure of 27 579 kPa (4,000 psi) for 2 minutes, and then
shall not rupture at less than 34 474 kPa (5,000 psi) (S6.2).
S5.3.6 Water absorption and tensile strength. A hydraulic brake
hose assembly, after immersion in water for 70 hours (S6.5), shall withstand
a pull of 1 446 N (325 pounds) without separation of the hose
from its end fittings (S6.4).
S5.3.7 Water absorption and whip resistance. A hydraulic brake
hose assembly, after immersion in water for 70 hours (S6.5), shall not
rupture when run continuously on a whip test flexing machine
for 35 hours (S6.3).
S5.3.8 Low-temperature resistance. A hydraulic brake hose conditioned
at -40°C (-40°F) for 70 hours shall not show cracks visible without
magnification when bent around a cylinder as specified in S6.6. (S6.6)
S5.3.9 Brake fluid compatibility, constriction, and burst strength.
Except for brake hose assemblies designed for use with mineral or petroleum-based
brake fluids, a hydraulic brake hose assembly shall meet the constriction
requirement of S5.3.1 after having been subjected to a temperature of
93.3°C (200°F) for 70 hours while filled with SAE RM-66-04 Compatibility
Fluid, as described in Appendix B of SAE Standard J1703 JAN 1995, Motor
Vehicle Brake Fluid. It shall then withstand water pressure of
27 579 kPa (4,000 psi) for 2 minutes and thereafter shall not rupture
at less than 34 474 kPa (5,000 psi) (S6.2). [SENTENCE DELETED]
S5.3.10 Ozone resistance. A hydraulic brake hose shall not show
cracks visible under 7-power magnification after exposure to ozone for
70 hours at 40°C (104°F) (S6.8).
S5.3.11 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, a hydraulic brake hose end fitting shall show no base metal
corrosion on the end-fitting surface, except where crimping or the application
of labeling information has caused displacement of the protective coating
(S6.9).
S6. Test procedures Hydraulic brake hose, brake
hose assemblies, and brake hose end fittings
S6.1 Expansion test
S6.1.1 Apparatus. Utilize a test apparatus (as shown in Figure 1)
which consists of:
(a) Source for required fluid pressure;
(b) Test fluid of water without any additives and free of gases;
(c) Reservoir for test fluid;
(d) Pressure gauges;
(e) Brake hose end fittings in which to mount the hose vertically; and
(f) Graduated burette with 0.5 mL (0.05 cc) increments.
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Figure 1 Expansion Test Apparatus
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S6.1.2 Preparation
(a) Measure the free length of the hose assembly.
(b) Mount the hose so that it is in a vertical, straight position without
tension when pressure is applied.
(c) Fill the hose with test fluid and bleed all gases from the system.
(d) Close the valve to the burette and apply 10 342 kPa (1,500
psi) for 10 seconds; then release pressure.
S6.1.3 Calculation of expansion at 6 895 kPa (1,000 psi) and
10 342 kPa (1,500 psi)
(a) Adjust the fluid level in the burette to zero.
(b) Close the valve to the burette, apply pressure at the rate of
103 421 kPa (15,000 psi) per minute, and seal 6 895 kPa (1,000
psi) in the hose (10 342 kPa [1,500 psi] in the second series).
(c) After 3 seconds, open the valve to the burette for 10 seconds and
allow the fluid in the expanded hose to rise into the burette.
(d) Repeat the procedure in steps (b) and (c) twice. Measure the amount
of test fluid which has accumulated in the burette as a result of the
three applications of pressure.
(e) Calculate the volumetric expansion per metre (foot) by dividing
the total accumulated test fluid by 3 and further dividing by the free
length of the hose in metres (feet).
S6.2 Burst strength test
(a) Connect the brake hose to a pressure system and fill it completely
with water, allowing all gases to escape.
(b) Apply water pressure of 27 579 kPa (4,000 psi) at a rate
of 103 421 kPa (15,000 psi) per minute.
(c) After 2 minutes at 27 579 kPa (4,000 psi), increase the pressure
at the rate of 103 421 kPa (15,000 psi) per minute until the pressure
exceeds 34 474 kPa (5,000 psi).
S6.3 Whip resistance test
S6.3.1 Apparatus. Utilize a test apparatus that is dynamically
balanced and includes:
(a) A movable header consisting of a horizontal bar equipped with capped
end fittings and mounted through bearings at each end to points 101.6
mm (4 inches) from the center of two vertically rotating disks whose
edges are in the same vertical plane;
(b) An adjustable stationary header parallel to the movable header in
the same horizontal plane as the centers of the disks, and fitted with
open end fittings;
(c) An elapsed time indicator; and
(d) A source of water pressure connected to the open end fittings.
S6.3.2 Preparation
(a) Except for the supplemental support specified in S6.3.2(d), remove
all external appendages including, but not limited to, hose armor, chafing
collars, mounting brackets, date band and spring guards.
(b) Measure the hose free length.
(c) Mount the hose in the whip test machine, introducing slack as specified
in Table II for the size of hose to be tested, measuring the projected
length parallel to the axis of the rotating disks. The manufacturer may,
at his option, adapt the fitting attachment points to permit the mounting
of hose assemblies equipped with angled or other special fittings in the
same orientation as hose assemblies equipped with straight fittings.
(d) In the case of a brake hose assembly equipped with a permanent supplemental
support integrally attached to the assembly, the assembly may be mounted
using the supplemental support and associated means of simulating its
attachment to the vehicle. Mount the supplemental support in the same
vertical and horizontal planes as the stationary header end of the whip
test fixture described in S6.3.1(b). Mount or attach the supplemental
support so that it is positioned in accordance with the recommendation
of the assembly manufacturer for attaching the supplemental support on
a vehicle.
Table II — Hose Lengths
Free
length between end fittings, mm (inches) |
Slack,
mm (inches) |
Hose
of 3 mm (1/8 inch) or less |
Hose
of more than 3 mm (1/8 inch) |
203.2
to 393.7
(8 to 15 1/2), inclusive |
44.45
(1.75) |
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254
to 393.7
(10 to 15 1/2), inclusive |
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25.4
(1.0) |
Over
393.7 to 482.6
(15 1/2 to 19), inclusive |
31.75
(1.25) |
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Over
482.6 to 609.6
(19 to 24), inclusive |
19.05
(0.75) |
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S6.3.3 Operation
(a) Apply 1 620 kPa (235 psi) water pressure and bleed
all gases from the system.
(b) Drive the movable head at 800 rpm.
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S6.4 Tensile strength
test
Utilize a tension testing machine conforming to the requirements of the
Methods of Verification of Testing Machines (1964 American Society
for Testing and Materials, Designation E 4)1
and provided with a recording device to give the total pull in Newtons
(pounds).
S6.4.1 Preparation. Mount the hose assembly to ensure a straight,
evenly distributed machine pull.
S6.4.2 Operation. Apply tension at a rate of 25.4 mm (1
inch) per minute of travel of the moving head until separation occurs.
S6.5 Water absorption sequence tests
S6.5.1 Preparation. Prepare three hose assemblies as follows:
(a) Remove 2.86 cm (1 1/8 inches) of hose cover, if any, from
the center of the hose assemblies without injury to any reinforcing material
or elongation of the hose assemblies.
(b) Measure the free length of the hose assemblies.
S6.5.2 Immersion and sequence testing
(a) Immerse the hose assemblies in distilled water for 70 hours.
(b) Thirty minutes after removal from water, conduct tests S6.2, S6.3,
and S6.4, using a different hose for each sequence.
S6.6 Low temperature resistance test
S6.6.1 Preparation
(a) Remove hose armor, if any, and condition a hose in a straight position
in air at -40°C (-40°F) for 70 hours.
(b) Condition a cylinder in air at -40°C (-40°F) for 70 hours,
using a cylinder of 63.5 mm (2 1/2 inches) in diameter for the
testing of a hose less than 3.2 mm (1/8 inch), 76.2 mm
(3 inches) for the testing of 1/8-inch or 3-mm hose, 88.9 mm (3
1/2 inches) for the testing of 3/16- and 1/4-inch hose or of 4-to-6-mm
hose, and 101.6 mm (4 inches) for the testing of hose greater
than 1/4 inch or 6 mm in diameter.
S6.6.2 Flexibility testing. Bend the conditioned hose 180 degrees
around the conditioned cylinder at a steady rate in a period of 3 to 5
seconds. Examine without magnification for cracks.
S6.7 Brake fluid compatibility test
S6.7.1 Preparation
(a) Attach a hose assembly below a 0.473-L (1-pint) reservoir
filled with 100 mL of SAE RM-66-04 Compatibility Fluid as shown in Figure
2. [SENTENCE DELETED]
(b) Fill the hose assembly with brake fluid, seal the lower end, and
place the test assembly in an oven in a vertical position.
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Figure 2 Brake Fluid Compatibility Apparatus
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S6.7.2 Oven treatment
(a) Condition the hose assembly at 93.3°C (200°F) for 70 hours.
(b) Cool the hose assembly at room temperature for 30 minutes.
(c) Drain the brake hose assembly, immediately determine that every inside
diameter of any section of the hose assembly, except for that part of
an end fitting which does not contain hose, is not less than 64 percent
of the nominal inside diameter of the hose, and conduct the test specified
in S6.2.
S6.8 Ozone resistance test
Utilize a cylinder with a diameter eight times the nominal outside diameter
of the brake hose, excluding armor.
S6.8.1 Preparation. After removing any armor, bind a hydraulic
brake hose 360° around the cylinder. In the case of hose shorter than
the circumference of the cylinder, bend the hose so that as much of its
length as possible is in contact.
S6.8.2 Exposure to ozone
(a) Condition the hose on the cylinder in air at room temperature for
24 hours.
(b) Immediately thereafter, condition the hose on the cylinder for 70
hours in an exposure chamber having an ambient air temperature of
40°C (104°F) during the test and containing air mixed with
ozone in the proportion of 50 parts of ozone per 100 million parts of
air by volume.
(c) Examine the hose for cracks under 7-power magnification, ignoring
areas immediately adjacent to or within the area covered by binding.
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S6.9 End fitting
corrosion resistance test
Utilize the apparatus described in ASTM B 117-64, Salt Spray (Fog)
Testing.1
S6.9.1 Construction. Construct the salt spray chamber so that:
(a) The construction material does not affect the corrosiveness of the
fog.
(b) The hose assembly is supported or suspended 30° from the vertical
and parallel to the principal direction of the horizontal flow of
fog through the chamber.
(c) The hose assembly does not contact any metallic material or any material
capable of acting as a wick.
(d) Condensation which falls from the assembly does not return to the
solution reservoir for respraying.
(e) Condensation from any source does not fall on the brake hose assemblies
or the solution collectors.
(f) Spray from the nozzles is not directed onto the hose assembly.
S6.9.2 Preparation
(a) Plug each end of the hose assembly.
(b) Mix a salt solution five parts by weight of sodium chloride to 95
parts of distilled water using sodium chloride substantially free
of nickel and copper and containing on a dry basis not more than
0.1 percent of sodium iodide and not more than 0.3 percent total impurities.
Ensure that the solution is free of suspended solids before the solution
is atomized.
(c) After atomization at 35°C (95°F), ensure that the collected
solution is in the pH range of 6.5 to 7.2. Make the pH measurements
at 25°C (77°F)
(d) Maintain a compressed air supply to the nozzle or nozzles that is
free of oil and dirt and between 68.9 and 172.4 kPa (10 and
25 psi.)
S6.9.3 Operation. Subject the brake hose assembly to the salt
spray continuously for 24 hours.
(a) Regulate the mixture so that each collector will collect from 1 to
2 mL of solution per hour for each 80 square centimeters of horizontal
collecting area.
(b) Maintain exposure zone temperature at 35°C (95°F).
(c) Upon completion, remove the salt deposit from the surface of the
hoses by washing gently or dipping in clean running water not warmer
than 37.8°C (100°F) and then drying immediately.
S7. Requirements Air brake hose, brake hose
assemblies, and brake hose end fittings
S7.1 Construction
Each air brake hose assembly shall be equipped with permanently attached
brake hose end fittings or reusable brake hose end fittings. Each
air brake hose constructed of synthetic or natural elastomeric rubber
intended for use with reusable end fittings shall conform to the dimensional
requirements specified in Table III. |
Table III Air Brake Hose Dimensions
for Reusable Assemblies
Size,
mm (inches) |
Inside
Diameter Tolerance,
mm (inches) |
Type I
Outside Diameter,
mm (inches) |
Type II
Outside Diameter,
mm (inches) |
Minimum |
Maximum |
Minimum |
Maximum |
4.76 (3/16) |
+0.66
(+0.026)
-0.00 |
11.99 (0.472) |
12.95 (0.510) |
12.70 (0.500) |
13.69 (0.539) |
6.35 (1/4) |
+0.79
(+0.031)
-0.00 |
13.59 (0.535) |
14.55 (0.573) |
14.27 (0.562) |
15.29 (0.602) |
7.94 (5/16) |
+0.79
(+0.031)
-0.00 |
15.19 (0.598) |
16.15 (0.636) |
16.66 (0.656) |
17.65 (0.695) |
9.53 (3/8) |
±0.58
(±0.023) |
18.26 (0.719) |
19.84 (0.781) |
18.26 (0.719) |
19.84 (0.781) |
10.32 (13/32) |
+0.79
(+0.031)
-0.00 |
18.14 (0.714) |
19.30 (0.760) |
18.85 (0.742) |
20.04 (0.789) |
12.7 (1/2) |
+0.99
(+0.039)
-0.00 |
20.52 (0.808) |
21.69 (0.854) |
22.81 (0.898) |
24.00 (0.945) |
15.88 (5/8) |
+1.07
(+0.042)
-0.00 |
23.70 (0.933) |
24.87 (0.979) |
26.77 (1.054) |
27.97 (1.101) |
12.7 (1/2)
special |
±0.79
(±0.031) |
21.44 (0.844) |
23.01 (0.906) |
21.44 (0.844) |
23.01 (0.906) |
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S7.2 Labeling
S7.2.1 [CONTENT DELETED]
S7.2.2 End fittings. Except for an end fitting that is attached
by deformation of the fitting about a hose by crimping or swaging, at
least one component of each air brake hose fitting shall be etched, embossed,
or stamped in block capital letters and numerals at least 1.6 mm
(one-sixteenth of an inch) high with the following information:
(a) The symbol DOT, constituting a certification by the manufacturer
of that component that the component conforms to all applicable motor
vehicle safety standards.
(b) A designation that identifies the manufacturer of that component
of the fitting, which shall be filed in writing with: Office of
Crash Avoidance Standards, Vehicle Dynamics Division, National Highway
Traffic Safety Administration, 400 Seventh Street, SW., Washington, DC
20590. The designation may consist of block capital letters,
numerals, or a symbol.
(c) The letter "A" shall indicate intended use in air brake systems.
In the case of an end fitting intended for use in a reusable assembly
with brake hose subject to Table III, "AI" or "AII" shall indicate use
with Type I or Type II hose, respectively.
(d) The nominal inside diameter of the hose to which the fitting is properly
attached expressed in inches or fractions of inches or in millimeters,
or the outside diameter of the plastic tubing to which the fitting is
properly attached expressed in inches or fractions of inches or in millimeters
followed by the letters OD. (See examples in S7.2.1(d).) The abbreviation
"mm" shall follow hose sizes that are expressed in millimeters.
S7.2.3 [CONTENT DELETED]
S7.2.3.1 At least one end fitting of an air brake hose assembly
made with end fittings that are attached by crimping or swaging shall
be etched, stamped, or embossed with a designation at least 1.6 mm
(one-sixteenth of an inch) high that identifies the manufacturer of the
hose assembly and is filed in accordance with S7.2.3(b).
S7.3 Test requirements
Each air brake hose assembly or appropriate part thereof shall be capable
of meeting any of the requirements set forth under this heading, when
tested under the conditions of S11 and the applicable procedures of S8.
However, a particular hose assembly or appropriate part thereof need not
meet further requirements after having met the constriction requirement
(S7.3.1) and then having been subjected to any one of the requirements
specified in S7.3.2 through S7.3.13.
S7.3.1 Constriction. Except for that part of an end fitting
which does not contain hose, every inside diameter of any section of an
air brake hose assembly shall be not less than 66 percent of the nominal
inside diameter of the brake hose.
S7.3.2 High temperature resistance. An air brake hose shall not
show external or internal cracks, charring, or disintegration visible
without magnification when straightened after being bent for 70 hours
at 100°C (212°F) over a cylinder having the radius specified in
Table IV for the size of hose tested (S8.1).
S7.3.3 Low temperature resistance. The outer cover of an air brake
hose shall not show cracks visible without magnification as a result of
conditioning at -40°C (-40°F) for 70 hours when bent around a
cylinder having the radius specified in Table IV for the size of hose
tested (S8.2). |
Table IV Air Brake Hose Diameters
and Test Cylinder Radii
Nominal diameter of hose in inches* |
1/8 |
3/16 |
1/4 |
5/16 |
3/8 |
13/32 |
7/16, 1/2 |
5/8 |
Nominal diameter of hose in mm |
3 |
4.5 |
6 |
8 |
|
10 |
12 |
16 |
Test cylinder radius in inches |
1.5 |
2 |
2.5 |
3 |
3 |
3.5 |
4 |
4.5 |
Test cylinder radius in mm |
38 |
51 |
64 |
76 |
89 |
89 |
102 |
114 |
* These sizes are listed to provide test values for brake hoses manufactured in
these sizes. They do not represent conversions.
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S7.3.4 Oil resistance. After immersion
in ASTM No. 3 oil for 70 hours at 100°C (212°F), the volume of
a specimen prepared from the inner tube and cover of an air brake hose
shall not increase more than 100 percent (S8.3).
S7.3.5 Ozone resistance. The outer cover of an air brake hose
shall not show cracks visible under 7-power magnification after exposure
to ozone for 70 hours at 40°C (104°F) (S8.4).
S7.3.6 Length change. An air brake hose (other than a coiled nylon
tube for use in an assembly that meets the requirements of Sec. 393.45
of Title 49 of the Code of Federal Regulations
this title) shall not contract in length more than 7 percent
nor elongate more than 5 percent when subjected to air pressure of
1 379 kPa (200 psi) (S8.5).
S7.3.7 Adhesion. Except for hose reinforced by wire, an air brake
hose shall withstand a tensile force of 35.6 N (8 pounds) per
25.4 mm (1 inch) of length before separation of adjacent
layers (S8.6).
S7.3.8 Air pressure. An air brake hose assembly shall contain
air pressure of 1 379 kPa (200 psi) for 5 minutes without loss
of more than 34.5 kPa (5 psi) (S8.7).
S7.3.9 Burst strength. An air brake hose assembly shall not rupture
when exposed to hydrostatic pressure of 5 516 kPa (800 psi) (S8.8).
S7.3.10 Tensile strength. An air brake hose assembly (other than
a coiled nylon tube assembly which meets the requirements of Sec. 393.45
of Title 49 of the Code of Federal Regulations
this title) designed for use between a frame and axle
or between a towed and a towing vehicle shall withstand, without separation
of the hose from its end fittings, a pull of 1 112 N (250 pounds)
if it is 1/4 inch or 6 mm or less in nominal internal diameter, or a pull
of 1 446 N (325 pounds) if it is larger than 1/4 inch or 6 mm
in nominal internal diameter. An air brake hose assembly designed for
use in any other application shall withstand, without separation of the
hose from its end fitting, a pull of 222.4 N (50 pounds) if it
is 1/4 inch or 6 mm or less in nominal internal diameter, 667 N
(150 pounds) if it is 3/8 or 1/2 inch or 10 mm to 12 mm in nominal internal
diameter, or 1 446 N (325 pounds) if it is larger than 1/2 inch
or 12 mm in nominal internal diameter (S8.9).
S7.3.11 Water absorption and tensile strength. After immersion
in distilled water for 70 hours (S8.10), an air brake hose assembly (other
than a coiled tube assembly which meets the requirements of Sec. 393.45
of Title 49 of the Code of Federal Regulations
this title) designed for use between a frame and an axle or between
a towed and a towing vehicle shall withstand, without separation of the
hose from its end fittings, a pull of 1 112 N (250 pounds) if
it is 1/4 inch or 6 mm or less in nominal internal diameter, or a pull
of 1 446 N (325 pounds) if it is larger than 1/4 inch or 6 mm
in nominal internal diameter. After immersion in distilled water for 70
hours (S8.10), an air brake hose assembly designed for use in any other
application shall withstand, without separation of the hose from its end
fitting, a pull of 222.4 N (50 pounds) if it is 1/4 inch or 6
mm or less in nominal internal diameter, 667 N (150 pounds) if
it is 3/8 inch or 1/2 inch or 10 to 12 mm in nominal internal diameter,
or 1 446 N (325 pounds) if it is larger than 1/2 inch or 12 mm
in nominal internal diameter (S8.9).
S7.3.12 Zinc chloride resistance. The outer cover of an air brake
hose shall not show cracks visible under 7-power magnification after immersion
in a 50 percent zinc chloride aqueous solution for 200 hours (S8.11).
S7.3.13 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, air brake hose end fittings shall show no base metal corrosion
on the end fitting surface, except where crimping or the application of
labeling information causes a displacement of the protective coating.
S8. Test procedures Air brake hose, brake hose
assemblies, and brake hose end fittings
S8.1 High temperature resistance test
(a) Utilize a cylinder having the radius indicated in Table IV for the
size of hose tested.
(b) Bind the hose around the cylinder and condition it in an air oven
for 70 hours at 100°C (212°F).
(c) Cool the hose to room temperature, remove it from the cylinder, and
straighten it.
(d) Without magnification, examine the hose externally and cut the hose
lengthwise and examine the inner tube.
S8.2 Low temperature resistance test
(a) Utilize a cylinder having the radius indicated in Table IV for the
size of hose tested.
(b) Condition the cylinder and the brake hose, in a straight position,
in a cold box at -40°C (-40°F) for 70 hours.
(c) With the hose and cylinder at -40°C (-40°F), bend the hose
180 degrees around the cylinder at a steady rate in a period of 3 to 5
seconds.
S8.3 Oil resistance test
Utilize three test specimens and average the results.
S8.3.1 Preparation. Fashion a test specimen by cutting a rectangular
block 50.8 mm (2 inches) long and not less than 8.47 mm
(one-third of an inch) in width, having a thickness of not more than
1.6 mm (one-sixteenth inch), from the brake hose and buff the specimen
on both faces to ensure smooth surfaces.
S8.3.2 Measurement
(a) Weigh each specimen to the nearest milligram in air (W1) and in distilled
water (W2) at room temperature. If wetting is necessary to remove air
bubbles, dip the specimen in acetone and thoroughly rinse it with distilled
water.
(b) Immerse each specimen in ASTM No. 3 oil for 70 hours at 100°C
(212°F) and then cool in ASTM No. 3 oil at room temperature for 30 to
60 minutes.
(c) Dip the specimen quickly in acetone and blot it lightly with filter
paper.
(d) Weigh each specimen in a tared weighing bottle (W3) and in distilled
water (W4) within five minutes of removal from the cooling liquid.
(e) Calculate the percentage increase in volume follows:
S8.4 Ozone resistance test
Conduct the test specified in S6.8 using an air brake hose.
S8.5 Length change test
(a) Position a test hose in a straight, horizontal position and apply
air pressure of 68.9 kPa (10 psi) thereto.
(b) Measure the hose to determine its original free length.
(c) Without releasing the 68.9 kPa (10 psi), raise the air pressure
to the test hose to 1 379 kPa (200 psi).
(d) Measure the hose under 1 379 kPa (200 psi) to determine the
final free length. An elongation or contraction is an increase or decrease,
respectively, in the final free length from the original free length of
the hose.
S8.6 Adhesion test
S8.6.1 Apparatus. A tension testing machine that is power-driven
and that applies a constant rate of extension is used for measuring the
force required to separate the layers of the test specimen. The apparatus
is constructed so that:
(a) The recording head includes a freely rotating form with an outside
diameter substantially the same as the inside diameter of the hose specimen
to be placed on it.
(b) The freely rotating form is mounted so that its axis of rotation
is in the plane of the ply being separated from the specimen and so that
the applied force is perpendicular to the tangent of the specimen circumference
at the line of separation.
(c) The rate of travel of the power-actuated grip is a uniform 25.4
mm (one inch) per minute and the capacity of the machine is such that
maximum applied tension during the test is not more than 85 percent nor
less than 15 percent of the machine's rated capacity.
(d) The machine produces a chart with separation as one coordinate and
applied tension as the other.
S8.6.2 Preparation
(a) Cut a test specimen of 25.4 mm (1 inch) or more in length
from the hose to be tested and cut the layer to be tested of that test
specimen longitudinally along its entire length to the level of contact
with the adjacent layer.
(b) Peel the layer to be tested from the adjacent layer to create a flap
large enough to permit attachment of the power-actuated clamp of the apparatus.
(c) Mount the test specimen on the freely rotating form with the separated
layer attached to the power-actuated clamp.
S8.6.3 [Reserved]
S8.6.4 Calculations
(a) The adhesion value shall be the minimum force recorded on the chart,
excluding that portion of the chart which corresponds to the initial and
final 20 percent along the displacement axis.
(b) Express the force in Newtons per metre (pounds per inch)
of length.
S8.7 Air pressure test
(a) Connect the air brake hose assembly to a source of air pressure.
(b) Apply 1 379 kPa (200 psi) air pressure to the hose and seal
the hose from the source of air pressure.
(c) After 5 minutes, determine the air pressure remaining in the test
specimen.
S8.8 Burst strength test
(a) Utilize an air brake hose assembly.
(b) Fill the hose assembly with water, allowing all gases to escape.
Apply water pressure at a uniform rate of increase of approximately
6 895 kPa (1,000 psi) per minute until the hose ruptures.
|
|
S8.9 Tensile strength
test
Utilize a tension testing machine conforming to the requirements of the
Methods of Verification of Testing Machines (1964 American Society
for Testing and Materials, Designation E 4)1
and provided with a recording device to register total pull in Newtons
(pounds).
(a) Attach an air brake hose assembly to the testing machine to permit
a straight, even machine pull on the hose.
(b) Apply tension at a rate of 25.4 mm (1 inch) per minute of
travel of the moving head until separation occurs.
S8.10 Water absorption and tensile strength
test
Immerse an air brake hose assembly in distilled water at room temperature
for 70 hours. Thirty minutes after removal from the water, conduct the
test specified in S8.9.
S8.11 Zinc chloride resistance test
Immerse an air brake hose in a 50 percent zinc chloride aqueous solution
at room temperature for 200 hours. Remove it from the solution and examine
it under 7-power magnification for cracks.
S8.12 End fitting corrosion resistance test
Conduct the test specified in S6.9 using an air brake hose assembly.
S9. Requirements Vacuum brake hose, brake hose
assemblies, and brake hose end fittings
S9.1 Labeling
S9.1.1 [CONTENT DELETED]
S9.1.2 End fittings. Except for an end fitting that is attached
by heat striking or by interference fit with a plastic vacuum hose or
that is attached by deformation of the fitting about a hose by crimping
or swaging, at least one component of each vacuum brake hose fitting shall
be etched, embossed, or stamped in block capital letters and numerals
at least 1.6 mm (one-sixteenth of an inch) high with the following
information:
(a) The symbol DOT, constituting a certification by the manufacturer
of that component that the component conforms to all applicable motor
vehicle safety standards.
(b) A designation that identifies the manufacturer of that component
of the fitting, which shall be filed in writing with: Office of
Crash Avoidance Standards, Vehicle Dynamics Division, National Highway
Traffic Safety Administration, 400 Seventh Street, SW., Washington, DC
20590. The designation may consist of block capital letters,
numerals, or a symbol.
(c) The letters "VL" or "VH" shall indicate that the end fitting is intended
for use in a light-duty or heavy-duty vacuum brake system, respectively.
(d) The nominal inside diameter of the hose to which the fitting is properly
attached expressed in inches or fractions of inches or in millimeters,
or the outside diameter of the plastic tubing to which the fitting is
properly attached expressed in inches or fractions of inches or in millimeters
followed by the letters OD. (See examples in S9.1.1(d).) The abbreviation
"mm" shall follow hose sizes that are expressed in millimeters.
S9.1.3 [CONTENT DELETED]
S9.1.3.1 At least one end fitting of a vacuum brake hose assembly
made with end fittings that are attached by crimping or swaging or of
a plastic tubing assembly made with end fittings that are attached by
heat shrinking or dimensional interference fit shall be etched, stamped,
or embossed with a designation at least 1.6 mm (one-sixteenth
of an inch) high that identifies the manufacturer of the hose assembly
and is filed in accordance with S9.1.3(b).
S9.2 Test requirements
Each vacuum brake hose assembly or appropriate part thereof shall be
capable of meeting any of the requirements set forth under this heading,
when tested under the conditions of S11 and the applicable procedures
of S10. However, a particular hose assembly or appropriate part thereof
need not meet further requirements after having met the constriction requirement
(S9.2.1) and then having been subjected to any one of the requirements
specified in S9.2.2 through S9.2.11.
S9.2.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a vacuum
brake hose assembly shall be not less than 75 percent of the nominal inside
diameter of the hose if for heavy duty, or 70 percent of the nominal inside
diameter of the hose if for light duty.
S9.2.2 High temperature resistance. A vacuum brake hose shall
not show external or internal cracks, charring, or disintegration visible
without magnification when straightened after being bent for 70 hours
at 100°C (212°F) over a cylinder having the radius specified in
Table V for the size of hose tested (S10.1).
S9.2.3 Low temperature resistance. A vacuum brake hose shall
not show cracks visible without magnification after conditioning at
-40°C (-40°F) for 70 hours when bent around a cylinder having the
radius specified in Table V for the size of hose tested (S10.2).
S9.2.4 Ozone resistance. A vacuum brake hose shall not show cracks
visible under 7-power magnification after exposure to ozone for 70 hours
at 40°C (104°F) (S10.3).
S9.2.5 Burst strength. A vacuum brake hose shall not rupture under
hydrostatic pressure of 2 413 kPa (350 psi) (S10.4).
S9.2.6 Vacuum. The collapse of the outside diameter of a vacuum
brake hose under internal vacuum of 88 kPa (26 inches of Hg) for
five minutes shall not exceed 1.6 mm (one-sixteenth of an inch)
(S10.5).
S9.2.7 Bend. The collapse of the outside diameter of a vacuum
brake hose at the middle point of the test length, when bent until the
ends touch, shall not exceed the values given in Table V for the size
of hose tested (S10.6). |
Table V Vacuum Brake Hose Test Requirements
Inside Diameter of Hose* |
High Temperature Resistance |
Low Temperature Resistance |
Hose Length |
Radius of Cylinder |
Hose Length |
Radius of Cylinder |
mm |
Inches |
mm Inches |
mm Inches |
mm Inches |
mm Inches |
5 |
7/32 |
203.2 8.0 |
38.10 1.50 |
444.5 17.5 |
76.2 3.0 |
6 |
1/4 |
228.6 9.0 |
38.10 1.50 |
444.5 17.5 |
76.2 3.0 |
|
9/32 |
228.6 9.0 |
44.45 1.75 |
482.6 19.0 |
88.9 3.5 |
8 |
11/32 |
228.6 9.0 |
44.45 1.75 |
482.6 19.0 |
88.9 3.5 |
10 |
3/8 |
254.0 10.0 |
44.45 1.75 |
482.6 19.0 |
88.9 3.5 |
|
7/16 |
279.4 11.0 |
50.80 2.00 |
520.7 20.5 |
101.6 4.0 |
|
15/32 |
279.4 11.0 |
50.80 2.00 |
520.7 20.5 |
101.6 4.0 |
12 |
1/2 |
279.4 11.0 |
50.80 2.00 |
520.7 20.5 |
101.6 4.0 |
16 |
5/8 |
304.8 12.0 |
57.15 2.25 |
558.8 22.0 |
114.3 4.5 |
|
3/4 |
355.6 14.0 |
63.50 2.50 |
609.6 24.0 |
127.0 5.0 |
|
1 |
406.4 16.0 |
82.55 3.25 |
723.9 28.5 |
165.1 6.5 |
Inside Diameter
of Hose* |
Bend Test |
Deformation —
Collapsed Inside Diameter
(Dimension D) |
Hose Length |
Maximum Collapse of Outside
Diameter |
mm |
Inches |
mm |
Inches |
mm |
Inches |
mm |
Inches |
5 |
7/32 |
177.8 |
7.0 |
4.37 |
11/64 |
1.19 |
3/64 |
6 |
1/4 |
203.2 |
8.0 |
2.38 |
3/32 |
1.59 |
1/16 |
|
9/32 |
228.6 |
9.0 |
4.76 |
12/64 |
1.59 |
1/16 |
8 |
11/32 |
279.4 |
11.0 |
5.16 |
13/64 |
1.98 |
5/64 |
10 |
3/8 |
304.8 |
12.0 |
3.97 |
5/32 |
2.38 |
3/32 |
|
7/16 |
355.6 |
14.0 |
6.75 |
17/64 |
1.98 |
5/64 |
|
15/32 |
355.6 |
14.0 |
6.75 |
17/64 |
1.98 |
5/64 |
12 |
1/2 |
406.4 |
16.0 |
5.56 |
7/32 |
3.18 |
1/8 |
16 |
5/8 |
558.8 |
22.0 |
5.56 |
7/32 |
3.97 |
5/32 |
|
3/4 |
711.2 |
28.0 |
5.56 |
7/32 |
4.76 |
3/16 |
|
1 |
914.4 |
36.0 |
7.14 |
9/32 |
6.35 |
1/4 |
* These sizes are listed to provide test values for brake hoses manufactured in
these sizes. They do not represent conversions.
|
S9.2.8 Swell. Following exposure to
Reference Fuel A, every inside diameter of any section of a vacuum brake
hose shall not be less than 75 percent of the nominal inside of the hose
if for heavy duty, or 70 percent of the nominal inside diameter of the
hose if for light duty. The vacuum brake hose shall show no leakage, and
there shall be no separation of the inner tube from the fabric reinforcement
of the hose in a vacuum test of 88 kPa (26 inches of Hg) for 10
minutes (S10.7).
S9.2.9 Adhesion. Except for hose reinforced by wire, a vacuum
brake hose shall withstand a force of 35.6 N (8 pounds) per
25.4 mm (1 inch) of length before separation of adjacent layers
(S10.8).
S9.2.10 Deformation. A vacuum brake hose shall return to 90 percent
of its original outside diameter within 60 seconds after five applications
of force as specified in S10.9, except that a wire-reinforced hose need
only return to 85 percent of its original outside diameter. In the case
of heavy-duty hose, the first application of force shall not exceed a
peak value of 311.4 N (70 pounds), and the fifth application of
force shall reach a peak value of at least 178 N (40 pounds).
In the case of light-duty hose, the first application of force shall not
exceed a peak value of 222.4 N (50 pounds), and the fifth application
of force shall reach a peak value of at least 89 N (20 pounds)
(S10.9).
S9.2.11 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, vacuum brake hose end fittings shall show no base metal
corrosion of the end fitting surface, except where crimping or the application
of labeling information has caused displacement of the protective coating.
S10. Test procedures Vacuum brake hose, brake
hose assemblies, and brake hose end fittings
S10.1 High temperature resistance test
Conduct the test specified in S8.1 using a vacuum brake hose with the
cylinder radius specified in Table V for the size of hose tested.
S10.2 Low temperature resistance test
Conduct the test specified in S8.2 using a vacuum brake hose with the
cylinder radius specified in Table V for the size of hose tested.
S10.3 Ozone resistance test
Conduct the test specified in S6.8 using a vacuum brake hose.
S10.4 Burst strength test
Conduct the test specified in S8.8 using a vacuum brake hose.
S10.5 Vacuum test
Utilize a 30.5-cm (12-inch) vacuum brake hose assembly sealed
at one end.
(a) Measure the hose's outside diameter.
(b) Attach the hose to a source of vacuum and subject it to a vacuum
of 88 kPa (26 inches of Hg) for 5 minutes.
(c) Measure the hose to determine the minimum outside diameter while
the hose is still subject to vacuum.
S10.6 Bend test
(a) Bend a vacuum brake hose of the length prescribed in Table V in the
direction of its normal curvature until the ends just touch, as shown
in Figure 3.
(b) Measure the outside diameter of the specimen at point A before and
after bending.
(c) The difference between the two measurements is the collapse of the
hose's outside diameter on bending.
|
Figure 3 Bend Test of Vacuum Brake Hose
|
S10.7 Swell test
(a) Fill a specimen of vacuum brake hose 30.5 cm (12 inches)
long with Reference Fuel A, as described in the Method of Test for
Change in Properties of Elastomeric Vulcanizers Resulting From Immersion
in Liquids (1964 American Society for Testing and Materials, Designation
D 471)1.
(b) Maintain reference fuel in the hose under atmospheric pressure at
room temperature for 48 hours.
(c) Remove the fuel and determine that every inside diameter of any section
of the brake hose is not less than 75 percent of the nominal inside diameter
of the hose for heavy-duty hose and 70 percent of the nominal inside diameter
of the hose for light-duty hose.
(d) Subject the hose specimen to a vacuum of 88 kPa (26 inches
of Hg) for 10 minutes.
S10.8 Adhesion test
Conduct the test specified in S8.6 using a vacuum brake hose.
S10.9 Deformation test
Table VI specifies the test specimen dimensions.
S10.9.1 Apparatus. Utilize a compression device equipped to measure
force of at least 444.8 N (100 pounds) and feeler gauges of sufficient
length to be passed completely through the test specimen.
S10.9.2 Operation
(a) Position the test specimen longitudinally in the compression device
with the fabric laps not in the line of the applied pressure.
(b) Apply gradually increasing force to the test specimen to compress
its inside diameter to that specified in Table VI (dimension D of Figure
4) for the size of hose tested.
(c) After 5 seconds, release the force and record the peak load applied.
(d) Repeat the procedure four times permitting a 10-second recovery period
between load applications.
|
Table VI Dimensions of Test Specimen
and Feeler Gauge for Deformation Test
Inside Diameter
of Hose* |
Specimen Dimension
(see Figure 4) |
Feeler Gauge Dimensions |
Depth |
Length |
Width |
Thickness |
mm |
Inch |
mm Inch |
mm Inch |
mm Inch |
mm
Inch |
5 |
7/32 |
1.19 3/64 |
25.4 1 |
3.18 1/8 |
1.19 3/64 |
6 |
1/4 |
1.59 1/16 |
25.4 1 |
3.18 1/8 |
1.59 1/16 |
|
9/32 |
1.59 1/16 |
25.4 1 |
3.18 1/8 |
1.59 1/16 |
8 |
11/32 |
1.98 5/64 |
25.4 1 |
4.76 3/16 |
1.98 5/64 |
10 |
3/8 |
2.38 3/32 |
25.4 1 |
4.76 3/16 |
2.38 3/32 |
|
7/16 |
1.98 5/64 |
25.4 1 |
6.35 1/4 |
1.98 5/64 |
|
15/32 |
1.98 5/64 |
25.4 1 |
6.35 1/4 |
1.98 5/64 |
12 |
1/2 |
3.18 1/8 |
25.4 1 |
6.35 1/4 |
3.18 1/8 |
16 |
5/8 |
3.97 5/32 |
25.4 1 |
6.35 1/4 |
3.97 5/32 |
|
3/4 |
4.76 3/16 |
25.4 1 |
6.35 1/4 |
4.76 3/16 |
|
1 |
6.35 1/4 |
25.4 1 |
6.35 1/4 |
6.35 1/4 |
*These sizes are listed to provide test
values for brake hoses manufactured in these sizes. They do not represent conversions.
Figure 4 Deformed Specimen of Vacuum
Brake Hose
|
S10.10 End fitting
corrosion resistance test
Conduct the test specified in S6.9 using a vacuum brake hose assembly.
S11. Test conditions
Each hose assembly or appropriate part thereof shall be able to meet
the requirements of S5, S7, and S9 under the following
conditions:
S11.1 The
temperature of the testing room is 23.9°C (75°F).
S11.2
Except for S6.6, S8.2, and S10.2, the test samples are stabilized at test
room temperature prior to testing.
S11.3
The brake hoses and brake hose assemblies are at least 24 hours old and
unused. |
ENDNOTE:
1 Please see subsection
106(3) of the Motor Vehicle Safety Regulations (MVSR) for an
alternative requirement.
|