ISO 7635:2006

INTERNATIONAL ISO
STANDARD 7635
Third edition
2006-06-01
Road vehicles — Air and air/hydraulic
braking systems of motor vehicles,
including those with electronic control
functions — Test procedures
Véhicules routiers — Systèmes de freinage à air comprimé ou
hydropneumatiques pour les véhicules à moteur, y compris les
systèmes à fonctions de commande électroniques — Méthodes d'essai

Reference number
©
ISO 2006
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©  ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Symbols . 4
5 Test site conditions . 6
5.1 Test site . 6
5.2 Road surface condition. 6
5.3 Ambient conditions . 7
6 General requirements. 7
7 Recommended sequence of the tests . 8
7.1 Preparation and static checks and tests. 8
7.2 Basic performance tests — Unladen . 9
7.3 Failure tests – Unladen. 9
7.4 ABS tests — Unladen . 9
7.5 ABS tests — Laden. 10
7.6 Failure tests — Laden. 10
7.7 Basic performance tests — Laden. 10
8 Vehicle preparation. 11
8.1 Documents and basic data . 11
8.2 Braking system condition and bedding . 11
8.3 Adjustment of braking equipment . 11
8.4 Tyre conditions . 11
8.5 Devices and instruments needed for the testing . 11
9 Static tests and checks . 13
9.1 Static braking force and control force vs. line pressure . 13
9.2 Capacity of energy sources. 13
9.3 Service braking system — Response time measurement. 14
9.4 Automatic braking . 15
9.5 Brake failure and defect warning signals. 15
9.6 Tests on vehicles equipped with spring brake actuators. 17
9.7 Additional tests on vehicles equipped with EBS . 18
10 Basic performance tests — Unladen . 18
10.1 Type 0 test (service braking system cold brake effectiveness, engine disconnected). 18
10.2 Type 0 test (service braking system cold brake, engine connected). 19
10.3 Parking braking system — Hill holding test . 19
10.4 Secondary braking system test. 19
10.5 Wheel locking sequence . 20
11 Failure tests — Unladen. 20
11.1 Service braking system partial failure test (type 0 test, cold brake effectiveness, engine
disconnected). 20
11.2 Failed load sensing device test/function test . 21
11.3 Failure of the energy source on vehicles equipped with EBS . 21
12 ABS tests — Unladen . 22
12.1 ABS failure. 22
12.2 Determination of the peak coefficient of adhesion on the high adhesion surface. 23
12.3 Determination of adhesion utilization on high adhesion surface. 24
12.4 Determination of adhesion utilization on low adhesion surface. 26
12.5 Additional checks . 26
13 ABS tests — Laden . 27
13.1 Additional split adhesion test. 27
13.2 Energy consumption on low adhesion surface . 27
14 Failure tests — Laden. 30
14.1 Service braking system partial failure test (type 0 test, cold brake effectiveness, engine
disconnected). 30
14.2 Failed load sensing device test . 30
14.3 Energy source failure test. 30
15 Basic performance tests — Laden . 30
15.1 Parking braking system — Hill holding test. 30
15.2 Parking braking system — Dynamic test . 32
15.3 Wheel locking sequence . 32
15.4 Type 0 test (service braking system cold brake effectiveness, engine disconnected). 32
15.5 Type 0 test (service braking system cold brake, engine connected) . 32
15.6 Warning device test . 33
15.7 Energy storage capacity test . 33
15.8 Type II or type IIA tests (downhill, endurance braking test). 33
15.9 Type I test (fade test) . 36
Annex A (normative) Typical braking equipment. 38
Bibliography . 40

iv © ISO 2006 – All rights reserved

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 7635 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking
systems and equipment.
This third edition cancels and replaces the second edition (ISO 7635:2003), which has been technically
revised.
INTERNATIONAL STANDARD ISO 7635:2006(E)

Road vehicles — Air and air/hydraulic braking systems of motor
vehicles, including those with electronic control functions —
Test procedures
1 Scope
This International Standard specifies the method of testing the air or air over hydraulic braking systems of
vehicles of categories M and N (excluding M1 and N1) as defined in Annex 7 to the UN-ECE Consolidated
Resolution on the Construction of Vehicles (R.E.3.) which are built to comply with UN-ECE Regulation 13/09
including supplements 1-6. Test methods covering lock actuators or the electrical regenerative braking
systems of electric and hybrid vehicles are not included in this edition.
NOTE Requirements of UN-ECE Regulation 13 related purely to the design of braking systems and braking system
components are not part of this International Standard.
The values in square brackets [ ] and the values in tables are taken from UN-ECE Regulation No. 13.
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 611:2003, Road vehicles — Braking of automotive vehicles and their trailers — Vocabulary
ISO
...