ISO 6118:2006

Road vehicles — Elastomeric cups and seals for cylinders for hydraulic braking systems using a non-petroleum base hydraulic brake fluid (service temperature 70 degrees C max.)

ISO 6118:2006 specifies performance tests of brake cups and seals for hydraulic braking systems for road vehicles. It does not include requirements relating to chemical composition, tensile strength and elongation of the rubber compound. Disc brake seals are not covered by this International Standard. ISO 6118:2006 is applicable to moulded seals (cups or double-lipped type gland seals), 60 mm in diameter and smaller, compounded from rubber, for use in hydraulic actuating cylinders employing road vehicle non-petroleum base hydraulic brake fluid conforming to the requirements of ISO 4925.

Véhicules routiers — Coupelles et joints en élastomère pour cylindres de systèmes de freinage hydrauliques utilisant un liquide de frein à base non pétrolière (température maximale d'utilisation: 70 degrés C)

General Information

• Status: Published
• Publication Date: 12-Jul-2006
• ICS: 43.040.40 - Braking systems
• ICS: 83.140.50 - Seals
• Technical Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Drafting Committee: ISO/TC 22/SC 33 - Vehicle dynamics and chassis components
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 23-Sep-2020

Relations

• Revises: ISO 6118:1980 - Road vehicles — Elastomeric cups and seals for hydraulic brake actuating cylinders using a non-petroleum base hydraulic brake fluid (service temperature 70 degrees C max.)
• Effective Date: 15-Apr-2008
• Consolidated By: ISO 21083-1:2018 - Test method to measure the efficiency of air filtration media against spherical nanomaterials — Part 1: Size range from 20 nm to 500 nm
• Effective Date: 06-Jun-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 6118
Second edition
2006-07-15
Road vehicles — Elastomeric cups and
seals for cylinders for hydraulic braking
systems using a non-petroleum base
hydraulic brake fluid (service temperature
70 °C max.)
Véhicules routiers — Coupelles et joints en élastomère pour cylindres de
systèmes de freinage hydrauliques utilisant un liquide de frein à base
non pétrolière (température maximale d'utilisation: 70 °C)

Reference number
ISO 6118:2006(E)
©
ISO 2006

---------------------- Page: 1 ----------------------
ISO 6118:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall
not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the
unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
©
ii ISO 2006 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 6118:2006(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 2
4.1 Workmanship and finish . 2
4.2 Marking . 2
4.3 Packaging . 2
4.4 Sampling . 2
5 Test requirements . 2
5.1 Resistance to fluid at elevated temperature . 2
5.2 Precipitation . 2
5.3 Wheel cylinder seals heat pressure stroking . 2
5.4 Master cylinder seals heat pressure stroking . 3
5.5 Low temperature performance . 4
5.6 Oven ageing . 4
5.7 Corrosion . 5
5.8 Storage corrosion test . 5
6 Test procedures . 5
6.1 Resistance to fluid at elevated temperature — Dimensional test . 5
6.2 Precipitation test . 7
6.3 Wheel cylinder seals heat pressure stroking . 8
6.4 Master cylinder seals heat pressure stroking . 10
6.5 Low temperature performance . 12
6.6 Oven ageing . 13
6.7 Hardness determination . 13
6.8 Corrosion test . 13
6.9 Storage corrosion test . 15
Bibliography . 16
©
ISO 2006 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 6118:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 6118 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking
systems and equipment.
This second edition cancels and replaces the first edition (ISO 6118:1980), which has been technically revised.
©
iv ISO 2006 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 6118:2006(E)
Road vehicles — Elastomeric cups and seals for cylinders for
hydraulic braking systems using a non-petroleum base
hydraulic brake fluid (service temperature 70 °C max.)
1Scope
This International Standard specifies performance tests of brake cups and seals for hydraulic braking systems
for road vehicles. It does not include requirements relating to chemical composition, tensile strength and
elongation of the rubber compound. Disc brake seals are not covered by this International Standard.
This International Standard is applicable to moulded seals (cups or double-lipped type gland seals), 60 mm in
diameter and smaller, compounded from rubber, for use in hydraulic actuating cylinders employing road vehicle
non-petroleum base hydraulic brake fluid conforming to the requirements of ISO 4925.
◦ ◦
NOTE The rubber used in these seals shall be suitable for operation in a temperature range of −40 C to +70 C.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and
100 IRHD)
ISO 188:1998, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests
ISO 4925, Road vehicles — Specification of non-petroleum-base brake fluids for hydraulic systems
ISO 4926, Road vehicles — Hydraulic braking systems — Non-petroleum base reference fluids
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
sloughing
release of carbon black on the surface of the rubber
3.2
scoring
formation of grooves in the rubber, parallel to the direction of travel of the piston or seal
3.3
scuffing
visible erosion of the outer surface of the rubber
©
ISO 2006 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 6118:2006(E)
4 General requirements
4.1 Workmanship and finish
Seals shall be free from blisters, pin-holes, cracks, protuberances, embedded foreign material or other physical
defects which can be detected by thorough inspection, and shall conform to the dimensions specified on the
drawings.
4.2 Marking
The identification mark of the manufacturer and other details as specified on drawings shall be moulded into
each seal. Each seal in conformity with this International Standard may also have the following mark:
“ISO 6118”.
4.3 Packaging
Seals shall be packaged to meet requirements specified by the purchaser.
4.4 Sampling
The minimum lot on which complete specification tests shall be conducted for quality control testing, or the
frequency of any specific type test used to control production, shall be agreed upon by the manufacturer and the
purchaser.
5 Test requirements
5.1 Resistance to fluid at elevated temperature
After being subjected to the test for resistance to compatibility fluid at elevated temperature as prescribed in 6.1,
the seals shall conform to the requirements specified in Table 1, and shall show no excessive disintegration as
evidenced by blisters or sloughing.
◦
70 C
Table 1 — Requirements for fluid resistance at elevated temperature ( )
Characteristics Permitted change
Volume From 0,0 %to +16,0 %
Outside diameter, lip
From 0,0 %to +5,75 %
Outside diameter, base
Hardness From −10 IRHDto 0 IRHD
5.2 Precipitation
0,3 %
Not more than sediment by volume shall be formed in the centrifuge tube after the seals have been tested
as specified in 6.2.
5.3 Wheel cylinder seals heat pressure stroking
5.3.1 General
Wheel cylinder seals when tested by the procedure specified in 6.3 shall meet the performance requirements
specified in 5.3.2 to 5.3.6.
©
2 ISO 2006 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 6118:2006(E)
5.3.2 Lip diameter change
The minimum lip diameter of wheel cylinder seals after the stroking test shall be greater than the wheel cylinder
bore by the minimum dimensions specified in Table 2.
Table 2 — Lip diameter change of wheel cylinder seals
Dimensions in millimetres
Diameter of wheel cylinder bore Minimum excess over bore
� 19,05 0,40
> 19,05� 25,4 0,50
> 25,4� 38,1 0,65
> 38,1� 60 0,75
5.3.3 Leakage
No constant dampness past the seals and no fluid discoloration of the filter paper on two or more inspections
shall occur.
5.3.4 Corrosion
Pistons and cylinder bore shall not show corrosion, as evidenced by pitting, to an extent discernible to the naked
eye, but staining or discoloration shall be permitted.
5.3.5 Change in hardness
Rubber seals shall not decrease in hardness by more than 10 IRHD when tested in accoprdance with the
procedure specified in 6.7.
5.3.6 Condition of test seals
Wheel cylinder seals shall not show excessive deterioration such as scoring, scuffing, blistering, cracking,
chipping (heel abrasion) or change in shape from original appearance.
5.4 Master cylinder seals heat pressure stroking
5.4.1 General
Master cylinder seals when tested by the procedure specified in 6.4 shall meet the performance requirements
specified in 5.4.2 to 5.4.6.
5.4.2 Lip diameter change
The minimum lip diameter of master cylinder seals after the stroking test shall be greater than the master
cylinder bore by the minimum dimensions specified in Table 3.
©
ISO 2006 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 6118:2006(E)
Table 3 — Lip diameter change of master cylinder seals
Dimensions in millimetres
Diameter of wheel cylinder bore Minimum excess over bore
� 19,05 0,30
> 19,05� 25,4 0,40
> 25,4� 38,1 0,50
> 38,1� 60 0,65
5.4.3 Leakage
Same requirement as specified for wheel cylinder seals shall be applied (see 5.3.3).
5.4.4 Corrosion
Same requirement as specified for wheel cylinder seals shall be applied (see 5.3.4).
5.4.5 Change in hardness
Same requirement as specified for wheel cylinder seals shall be applied (see 5.3.5).
5.4.6 Condition of the test seals
Same requirement as specified for wheel cylinder seals shall be applied (see 5.3.6).
5.5 Low temperature performance
5.5.1 Leakage
No leakage of fluid shall occur when seals are tested according to the procedure specified in 6.5.1.
5.5.2 Bend test
The seal shall not crack and shall return to its approximately original shape within 1 min when tested in
accordance with the procedure specified in 6.5.2.
5.6 Oven ageing
5.6.1 General
Seals when tested according to the procedure specified in 6.6 shall meet the requirements specified in 5.6.2
and 5.6.3.
5.6.2 Change in hardness
The change in hardness shall be within the limits of ±5 IRHD.
5.6.3 Condition of the test seals
The seal shall show no evidence of deterioration, or change in shape from original appearance.
©
4 ISO 2006 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 6118:2006(E)
5.7 Corrosion
5.7.1 General
Seals when tested in accordance with the procedure specified in 6.8 shall meet the requirements specified in
5.7.2 and 5.7.3.
5.7.2 Corrosion of metal strips
The seals shall not cause corrosion exceeding the limits shown in Table 4. The metal strips outside of the area
where the strips are in contact shall be neither pitted nor roughened to the extent discernible to the naked eye,
but staining or discoloration is permitted.
Table 4 — Permissible change in mass of corrosion test strips
Permissible change in mass
Test strips
2
mg/cm
of surface
Tinned iron ±0,2
±0,2
Steel
±0,1
Aluminium
±0,2
Cast iron
±0,4
Brass
±0,4
Copper
±0,4
Zinc
5.7.3 Fluid-water mixture characteristics
◦ ◦
The fluid-water mixture at the end of the test shall show no gelling at 23 C± 5 C. No crystalline-type deposits
shall form and adhere to either the glass wall or the surface of metal strips. The fluid-water mixture shall contain
no more than 0,2 % sediment by volume.
5.8 Storage corrosion test
After 12 cycles in the humidity cabinet when operated in accordance with the procedure specified 6.9, there
shall be no evidence of corrosion adhering to or penetrating the wall of the cylinder bore that was in contact with
the test seal.
Slight discoloration (staining) or any corrosion or spots away from the contact surface of the test seals may be
permissible.
6 Test procedures
6.1 Resistance to fluid at elevated temperature — Dimensional test
6.1.1 Apparatus and material
The following apparatus and material shall be used for the test.
6.1.1.1 Micrometer, shadowgraph or other suitable apparatus, to measure accurately to 0,02 mm.
6.1.1.2 Glass container, of capacity approximately 250 ml and diameter 50 mm, which can be tightly sealed.
6.1.1.3 Chemical balance, capable of weighing to 1mg.
©
ISO 2006 – All rights reserved 5

---------------------- Page: 9 ----------------------
ISO 6118:2006(E)
6.1.1.4 Oven, uniformly heated dry air type, conforming to the requirements for method B of ISO 188:1998.
6.1.1.5 Two glass-stoppered weighing bottles, of adequate mouth size to hold the seals under test.
6.1.1.6 Isopropyl or ethyl alcohol, of 95 % (by volume) reagent grade for washing purpose.
6.1.2 Test specimens
◦
Two seals shall be used for testing at 70 C.
6.1.3 Test procedure
Rinse the cups in the alcohol (6.1.1.6) and wipe dry with a clean, lint-free cloth to remove dirt and packing
debris. Do not leave the seals in the alcohol for more than 30 s.
Measure the lip and base diameters to the nearest 0,02 mm, taking the average of two readings at right angles
to one another. Take care when measuring the diameters before and after ageing that the measurements are
made in the same manner and at the same locations.
Determine and record the initial hardness of the test seals. (See 6.7 and Figure 3.)
Determine the volume of each seal in the following manner: weigh the seals in air (m ) to the nearest 0,001 g
1
and then weigh the seals immersed in distilled water at room temperature (m ). Quickly dip each specimen in
2
alcohol and then blot dry with filter paper free of lint and foreign material.
Immerse two seals completely in 75 ml±1ml of compatibility reference fluid as defined in ISO 4926, in the
glass container (6.1.1.2) and seal the container to prevent vapour loss. Place the container in the oven (6.1.1.4)
◦ ◦
set at 70 C± 2 C for a period of 120 h±2h. At the end of the heating period, remove the container from the
◦ ◦
oven and allow the seals to cool in the container at 23 C± 5 C for 60 min to 90 min. At the end of the cooling
period, remove the seals from the container and rinse in the alcohol and wipe dry with a clean, lint-free cloth. Do
not allow the seals to remain in the alcohol for more than 30 s.
After removal from the alcohol and drying, place each seal in a separate, tarred, stoppered weighing bottle
(6.1.1.5) and weigh (m ). Remove each seal from its weighing bottle and weigh immersed in distilled water
3
(m ) to determine water displacement after hot fluid immersion. Make all weighings to the nearest 0,001 g.
4
Determine the final volume, dimensions and hardness of each seal within 60 min of rinsing in the alcohol.
6.1.4 Expression of results
6.1.4.1 Volume change
Volume change ∆V shall be reported as a percentage of the original volume. The change in volume is given by
the formula:
(m − m )− (m − m )
3 4 1 2
∆V = × 100
(m − m )
1 2
where
m is the initial mass in air, in grams;
1
m is the initial apparent mass in water, in grams;
2
m is the mass in air after immersion in test fluid, in grams;
3
m is the apparent mass in water after immersion test fluid, in grams.
4
©
6 ISO 2006 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 6118:2006(E)
6.1.4.2 Dimensional change
The original measurements of the lip and base diameters shall be subtracted from measurements taken after
the test and the difference reported in millimetres and as percentages of the original diameters.
6.1.4.3 Hardness
Change in hardness shall be determined and recorded.
6.1.4.4 Disintegration
The seals shall be examined for disintegration as evidenced by blisters or sloughing.
6.2 Precipitation test
6.2.1 Apparatus
The following apparatus shall be used for the test.
250 ml 50 mm
6.2.1.1 Glass containers, of capacity approximately and diameter , which can be tightly sealed.
100 ml
6.2.1.2 Cone-shaped centrifuge tube, of capacity .
6.2.1.3 Oven, uniformly heated dry air type, conforming to the requirements for Method B of ISO 188:1998.
6.2.2 Test specimen
From two or more seals to be tested, obtain a sample of mass 4,0 g± 0,5 g. Since sizes of seals vary, small
pieces may be cut from the seal to arrive at the mass. Use the minimum number of pieces to obtain a mass of
4,0 g± 0,5 g.
6.2.3 Test procedure
To determine the precipitation compatibility characteristics of the test seals, place the sample (6.2.2) in one of
the specified glass containers (6.2.1.1) containing 75 ml of compatibility fluid of ISO 4926. Seal the container to
◦ ◦
prevent vapour loss and place in an oven (6.2.1.3) at 70 C± 2 C for 120 h±2h.
As an optional test, a blank test may be run on the brake fluid prior to the test and any sediment from the blank
test may be subtracted from the sediment amount obtained from the test.
At the end of the heating period, remove the container from the oven and allow to cool at room temperature for
24 h, after which remove the seals.
Agitate thoroughly the contents of the jar and transfer the fluid and suspended particles to a cone-shaped
centrifuge tube (6.2.1.2) of 100 ml capacity and determine the sediment as follows.
a) Measure a 10 ml sample of the fluid and suspended particles to be tested in each of two clean, dry
centrifuge tubes at room temperature. Fill each tube to the 100 ml mark with the naphtha (see caution
below) and close tightly with a softened cork (not a rubber stopper). Then invert each tube at least 20 times,
allowing the liquid to drain thoroughly from the tapered tip of the tube each time. Place the tubes in a water
◦ ◦
bath at 32 C to 35 C for 5 min. Momentarily remove the corks to relieve any pressur
...