ISO 6120:1986

International Standard @ 6120
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*MEXiiYHAPOiiHAfl OPïAHM3AUHR il0 CTAHLlAPTH3AUHM.ORGANlSATlON INTERNATIONALE DE NORMALISATION
Road vehicles - Brake hose assemblies for hydraulic
a
braking systems used with a petroleum-base hydraulic
fluid
Véhicules routiers - Flexibles pour systèmes de freinage hydraulique utilisant un liquide de frein à base pétrolsre
First edition - 1986-12-15
- w UDC 621.643.3: 629.11-592.2 Ref. No. IS0 6120-1986 (E)
@
Descriptors : road vehicles, braking systems, hydraulic brakes, hoses, performance tests, marking.
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Price based on 11 pages
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I Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
at
the IS0 Council. They are approved in accordance with IS0 procedures requiring
least 75 % approval by the member bodies voting.
International Standard IS0 6120 was prepared by Technical Committee ISO/TC 22,
Road vehicles.
Users should note that all International Standards undergo revision from time to time
and that any reference made herein to any other International Standard implies its
latest edition, unless otherwise stated.
O International Organization for Standardization, 1986 @
Printed in Switzerland

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IS0 6120-1986 (E)
INTERNATIONAL STANDARD
Road vehicles - Brake hose assemblies for hydraulic
braking systems used with a petroleum-base hydraulic
fluid
4 Definitions
1 Scope
This International Standard specifies the test procedures for,
4.1 brake hose assembly : Brake hose equipped with end
and performance requirements of, hydraulic brake hose
fittings for use in a brake system.
assemblies to be used in hydraulic braking systems of road
vehicles, and the markings to be put on the brake hose
4.2 brake hose : Flexible conduit manufactured for use in a
assembly when manufactured according to these specifica-
brake system to transmit and contain the fluid pressure medium
tions.
used to apply force to the vehicle's brakes.
4.3 brake hose end fittings : Coupling designed for perma-
2 Field of application nent attachment to the ends of a brake hose by crimping or
swaging.
This International Standard applies to brake hose assemblies
made of a hose fabricated from cord and synthetic elastomers
4.4 free length : Linear measurement of brake hose ex-
and assembled with metal end fittings for use with petroleum-
posed between the end fittings of a brake hose assembly while
base brake fluids in accordance with IS0 7308.
maintained straight.
The nominal internal diameter of the hose shall be one of the
4.5 leaks; burst : Loss of test fluid through the brake hose
following values :
assembly other than by the designed inlet(s) and outlet(s).
3,2 mm 4,8 mm 6,3 mm
4.6 cracking : Interruption of a surface due to environment
andlor stress.
3 References
5 Construction
IS0 3768, Metallic coatings - Neutral salt spray test (NSS
test).
5.1 Hose
IS0 3996, Road vehicles - Brake hose assemblies for hydraulic The hose shall consist of an elastomeric lining, two or more
layers or plies of reinforcing cord embedded in, and/or bonded
braking systems used with a non-petroleum-base hydraulic
fluid. to, the elastomeric lining and outer cover. A cushion liner be-
tween the reinforcing cords is permitted. The cover shall be a
black compound which will not crack when subjected to long
IS0 7308, Road vehicles - Petroleum base brake fluid for
periods of weather ageing. The lining of this hose shall be of a
hydraulic braking devices with stored energy. 1 )
compound which will effectively resist deterioration by
petroleum brake fluids as designated in clause 2.
IS0 7309, Road vehicles - Hydraulic braking systems - IS0
reference petroleum base fluid.
5.2 Hose assembly
IS0 75001 1, Metallic materials - Verification of static uniaxial Each hydraulic brake hose assembly shall have permanently at-
tached end fittings.
testing machines - Part 1 : Tensile testing machines.
1) At present at the stage of draft.
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IS0 6120-1986 (E)
For the last 4 h prior to testing, they shall be maintained at a
6 Performance testing for acceptance
temperature of 15 to 32 OC.
6.1 Test schedule
Prior to installation of the hose assembly on a whip test or cold
bend test, all external appendages such as mounting brackets,
The test schedule shall consist of all the tests listed in table 1.
spring guards, and metal collars shall be removed or long tubes
The complete test schedule shall be conducted for each
shortened, or both.
separate brake hose assembly design. For the purposes of this
test schedule, any changes in hose construction or materials,
The temperature of the test room shall be between 15 and
coupling crimp or swage design or end fittings shall be deemed
32 OC for all tests except cold bend, ozone, salt spray and brake
to constitute a change in assembly design. Variations that do
fluid compatibility.
not influence the integrity of the hose coupling joint such as
variation in thread size, port dimensions, hexagon size and the
like shall not be considered a design change.
7.2 100 YO pressure test
The hose assembly shall be subjected to a pressure test, using
6.2 Requirements
IS0 7309 as
inert gas, air, water or brake fluid conforming to
the pressure medium. The test pressure shall be 10,3 MPa
Except for the 100 % pressure test and constriction test, in the
minimum, 14.5 MPa maximum for inert gas and air, and
event of a failure of one sample in performance testing, a
20,7 MPa minimum, 24,8 MPa maximum for water and
double sample retest of that characteristic shall be performed
petroleum-base hydraulic brake fluid. Special care shall be
as shown in table 1.
taken when gas or air is used, as under the pressure specified,
gas and air are explosive if a failure should occur in the hose
Table 1 - Hydraulic brake hose assembly performance
assembly. The pressure shall be held for not less than 10 s and
test and quantity of samples required11
not more than 25 s. Hose assemblies showing leaks under this
test shall be rejected and destroyed.
i Sample size I
Qualification test Sub-clause
Original Retest
I test I 7.3 Constriction test
II
All 1 AH I 100 % pressure test 1 7.2
7.3.1 Requirements
AM) I Constriction I 7.3
Volumetric expansion
The constriction of the hose assemblies s. .dl -3 measured with
followed by burst
a gauge plug as shown in figure 1, the A dimensions of which
I 4 I 8 I Brake fluid compatibility I 7.6 I
shall be as listed in table 2. The constriction requirements do
not apply to that part of the brake hose end fittings which does
4 8 Whip 7.7
not contain hose.
4 8 I Tensile I 7.8
I 1 I 2 I Cold bend I 7.10 I
Table 2 - Constriction gauge dimensions
1 2 Ozone 7.11
Dimensions in millimetres
1 2 Salt spray 7.12
Hose internal diameter
Tests after water absorption Diameter A, min.
32 2,03
4 8 Burst
48 3,05
4 8 Whip 1 7.9
63 4,19
4 8 Tensile
31 - Total quantity of samples
7.3.2 Procedure
Hold the assembly vertically at the fitting and insert the A
Failure of any one sample on retest shall be cause for dis-
diameter portion of the gauge plug into the end of the fitting for
qualification or rejection of the lot3).
the full length of the probe. Repeat at the other end of the
brake hose assembly.
7 Tests
Some hose assemblies have a fitting so designed that it is im-
7.1 Test conditions possible to insert the gauge plug externally. For these
assemblies, insert a special elongated gauge plug into the op-
posite fitting as above and pass the probe through the hose,
The assemblies for the performance test shall be new and un-
into and through the crimped area of the fitting being tested. If
used and shall be at least 24 h old.
1) When the hose assembly configurations are such that it is impractical to conduct tests such as tensile, whip and constriction, hose assemblies
produced from equivalent type end fittings, production type equipment and processes shall be used as substitute brake hose assemblies.
2) Four brake hose assemblies on original test and eight brake hose assemblies on retest may be used if assemblies must be cut to conduct constric-
tion tests.
3) Lot : a defined quantity of brake hose or brake hose assemblies which is being qualified by the test.
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IS0 6120-1986 (E)
the gauge plug becomes misaligned at the entrance to the 7.4.3 Calibration of apparatus
second fitting, it may be necessary to align the hose to allow
the gauge plug to pass through. The special gauge plug shall The apparatus shall be tested prior to use to determine its
meet all the requirements of figure 1, with the exception of the calibration correction factors established at pressures of
76 mm length, which shall be increased appropriately so that its 6,9 and 10,3 MPa using a simulated hose assembly that shall
consist of 1,52 mm minimum wall hydraulic steel tubing with a
tip will extend past the hose opening.
free length of 305 f 6 mm and an outside diameter of 6,3 mm.
All fittings and adaptors used in the testing of the hose
Some brake hose assemblies have fittings on both ends which
assembly shall be in this system. This may require the attach-
cannot be entered with the gauge plug. Cut these assemblies
50 f 2 mm from the end of the fitting and then test with the ment of the tubing to the brake hose fittings in the case of
special end configurations. The calibration correction factors
gauge plug (see table 1, note 2).
shall be subtracted from the expansion readings obtained on
the test specimens. The maximum permissible calibration cor-
rection factor shall be 0,08 cm3 at 10,3 MPa.
7.4 Expansion test
7.4.4 Procedure
7.4.1 Requirements
The expansion test is designed to measure, by fluid displace-
7.4.4.1 If the specimen to be used in this test has been sub-
ment, the volumetric expansion of the free length of a brake
jected to a pressure above 10,3 MPa using any medium prior to
hose assembly when subjected to specified internal pressures.
0 this test, allow it to recover for 15 min.
The free length is the length measured between the fittings.
The maximum expansion of any of the hose assemblies so
tested shall not exceed the values in table 3.
7.4.4.2 Carefully thread the hose assembly into the adaptors
designed to seal in the same manner as in actual use. Do not
twist. Maintain the hose vertical and straight without tension
while under pressure.
Table 3 - Maximum expansion of free length hose
I 6.9 MPa 10.3 MPa 7.4.4.3 Bleed all the air from the system by allowing ap-
proximately 0,25 I of water to flow from the reservoir rank
Regular Low Regular
interna' expansion expansion
through the hose assembly and into the burette. Removal of air
diameter
(HR) 1 (HL)
bubbles may be facilitated by shaking the hose. Close the valve
mm crn3/m cm3/rn cm3/ m
to the burette and apply 10,3 -g,14 MPa pressure to the hose
assembly. Within 10 s inspect the hose assembly for leaks at
3,35 2,36
the connections and then release the pressure completely in the
3,41 2.69 4,27
hose. Adjust the water level in the burette to zero. With the
- MPa to the hose
valve to the burette closed, apply 6,9
assembly and seal this pressure in the hose within 5 k 3 s.
7.4.2 Apparatus Within 3 s open the valve to the burette for 10 f 3 sand allow
the water in the expanded hose to rise in the burette. The water
The apparatus shall consist essentially of the following level in the burette should become constant within that time
0
period.
a) source for required fluid pressures;
7.4.4.4 Repeat the preceding step twice, so that the amount
b) test fluid consisting of water without any additives and
of water in the burette will be the total of the three expansions.
free of air or gas bubbles;
Measure this burette reading to the nearest 0,05 cm3.
c) reservoir for water pressure gauges;
7.4.4.5 The volumetric expansion is calculated by dividing the
d) fittings in which the hose assembly may be mounted
burette reading by three and subtracting the calibration factor.
vertically for application of pressure under controlled
This figure divided by the free length in metres will give the
conditions;
volumetric expansion per metre of hose.
e) graduated burette with 0,05 cm3 increments for
7.4.4.6 Readjust the water level in the burette to zero as
measuring the volume of liquid corresponding to the expan-
above and repeat the procedure to obtain the expansion at a
sion of the hose under pressure;
pressure of 10,3 - 8,,4 MPa. If the pressure in the hose should
inadvertently be raised to a value above that specified, but not
f) plumbing hardware as required.
above 24 MPa, completely release the pressure and allow the
hose to recover for at least 15 min and then repeat the test. If
All piping and connections shall be smooth bore without
the hose was subjected to a pressure above 24 MPa, then
recesses or offsets, so that all air may be freely removed from
repeat the test using a new brake hose. If, at any time during
the system before running each test. Valves shall be capable of
the test, an air bubble flows out of the hose, repeat the test
withstanding the pressures involved without leakage (see
after allowing at least 5 min for the hose to recover.
figure 2).
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IS0 6120-1986 (E)
7.6.2 Preparation
7.5 Burst strength test
7.5.1 Requirements 7.6.2.1 Attach a hose assembly or manifold to which multiple
hose assemblies may be attached, below a 0,5 I reservoir filled,
When tested under hydraulic pressure, each sample of hose
as shown in figure 3, with 100 ml of IS0 7309 compatibility
assembly shall withstand a pressure hold of 2 min at the
petroleum-base hydraulic brake fluid.
specified pressure and shall withstand the minimum burst
pressure as shown in table 4.
7.6.2.2 Fill the hose assembly with compatibility petroleum-
base hydraulic brake fluid, seal the lower end, and place the
test assembly in an oven in a vertical position.
Table 4 - Hold pressure and minimum burst pressure
Hose internal Pressure Minimum 7.6.3 Procedure
diameter burst pressure
7.6.3.1 Condition the hose assembly at 93 + :OC for 70
3,2 - 4,8 - 6,3 34,5
to 72 h.
7.6.3.2 After completion of the test period, remove the hose
f 5 min.
assembly and cool at room temperature for 30
7.5.2 Apparatus
7.6.3.3 Drain the brake hose and within 10 min verify the con-
The apparatus shall consist of a suitable pressure system in
striction requirements according to 7.3.1 and 7.3.2.
which the hose is so connected that controlled and measured
fluid pressure may be applied internally. The pressure shall be
obtained by means of a hand- or power-driven pump or an ac-
7.6.3.4 The brake hose assembly shall burst within 3 h
cumulator system and shall be measured with a calibrated
using
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