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: 9020 - International Standard under periodical review
• Start Date: 15-Jul-2025
• Completion Date: 15-Jul-2025

Relations

• 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
• 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

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 2006
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ii ISO 2006 – All rights reserved

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
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ISO 2006 – All rights reserved iii

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

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
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ISO 2006 – All rights reserved 1

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.
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2 ISO 2006 – All rights reserved

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.
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ISO 2006 – All rights reserved 3

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.
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4 ISO 2006 – All rights reserved

5.7 Corrosion
5.7.1 General
Seals when tested in accordance with the proced
...