ISO 15484:2008

INTERNATIONAL ISO
STANDARD 15484
First edition
2008-08-01
Road vehicles — Brake lining friction
materials — Product definition and
quality assurance
Véhicules routiers — Matériaux de friction pour garnitures de freins —
Définition du produit et assurance qualité

Reference number
©
ISO 2008
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ii © ISO 2008 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Symbols and abbreviated terms . 2
5 Product quality preplanning and test plan. 3
5.1 General. 3
5.2 Procedure . 3
5.3 Phases of product quality preplanning . 4
5.4 Test plan . 4
6 Checks and requirements — Brake lining complete. 8
6.1 General (visual, dimensional and material checks) . 8
6.2 Physical properties. 9
6.3 Corrosion (backing plate and shoe surface treatment). 12
6.4 Friction performance passenger cars . 12
6.5 Friction performance commercial vehicles . 13
7 Documentation in the lining data sheet (LDS). 14
8 Ongoing production monitoring . 14
Annex A (informative) Example of lining data sheet (LDS). 15
Bibliography . 20

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 15484 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking
systems and equipment.
iv © ISO 2008 – All rights reserved

Introduction
Drum and disc brake friction materials are important functional parts of the wheel brakes. They are pressed
against the rotating brake drum or disc by a clamping force applied by the actuating mechanism of the brake
during a braking operation. The kinetic energy of the vehicle is thereby largely transformed into heat. The
brake pad or lining is of essential importance for the effectiveness and user comfort of the brake system. Disc
brake pads consist of the friction material itself, the pad carrier plate and, in some cases, silencing parts, pad
wear warning devices and retaining or guiding elements. The friction material is usually permanently bonded
to the backing plate by a bonding process in which the friction material is subjected to both heat and pressure.
Underlayers can be inserted between the friction material and backing plate to improve bond strength and
other properties. Drum brake linings consist of the friction material itself, usually shaped to match the radius of
the brake shoe onto which it is subsequently attached. The friction material is usually attached to the
supporting brake shoe either by bonding or by the use of rivets. Conventional friction materials consist mainly
of fibrous materials, bonding agents, anti-seize agents, metals and other fillers. The friction material type, and
any backing plates, anti-noise measures, pad springs and pad wear warning devices, etc., are defined in the
relevant figure.
The basic aim of this International Standard is:
⎯ to ensure the product is verified and validated during all project phases for transfer into series production;
⎯ to increase product reliability and at the same time limit the cost of testing;
⎯ to identify the necessary test standards to equally cover brake performance and noise.
Visibility of production spread and the opportunity to select parts for testing from assorted areas of
compressibility are the main reasons for the statistical evaluation. The procedures described in this
International Standard are based on ISO/TS 16949 and encompass the entire product quality preplanning
process, from the definition phase up to the determination of parameters for series production. These are
defined in this International Standard as phases 1 to 7.

INTERNATIONAL STANDARD ISO 15484:2008(E)

Road vehicles — Brake lining friction materials — Product
definition and quality assurance
1 Scope
The procedures in this International Standard apply to disc brake pads and drum brake linings for motor
vehicles and describe systematic processes for the quality assurance of such brake linings.
In conjunction with tolerance ranges, the test methods and results described in this International Standard
permit a rapid assessment of disc brake pads.
Uniform handling of the procedures through various phases ensures that the quality assurance requirements
are clearly understood and that a global implementation is possible in the relationship between customers and
suppliers.
This International Standard relates to the completed friction material and is applicable during product
development to the quality assurance of ongoing series production, focussing on the “component” friction
material. It is advisable that tests with apparent “system” character be avoided.
Raw material checks and processing control are outside the scope of this International Standard.
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 2812-1, Paints and varnishes — Determination of resistance to liquids — Part 1: Immersion in liquids
other than water
ISO 6310, Road vehicles — Brake linings — Compressive strain test method
ISO 6312, Road vehicles — Brake linings — Shear test procedure for disc brake pad and drum brake shoe
assemblies
ISO/PAS 22574, Road vehicles — Brake linings friction materials — Visual inspection
ISO 26865, Road vehicles — Brake lining friction materials — Standard performance test procedure for
commercial vehicles with air brakes
ISO 26866, Road vehicles — Brake lining friction materials — Standard wear test procedure for commercial
vehicles with air brakes
ISO 26867, Road vehicles — Brake lining friction materials — Friction behaviour assessment for automative
brake systems
ISO 27667, Road vehicles — Brake lining friction materials — Evaluation of corrosion effects on painted
backing plates and brake shoes
JASO C458-86, Test procedure of pH for brake linings, pads and clutch facings of automobiles
JIS D 4311, Clutch facings for automobile
JIS D 4421, Method of hardness test for brake linings, pads and clutch facings of automobiles
SAE J2598, Automotive disc brake pad natural frequency and damping test
1)
SAE J2694, Anti-noise shims: T-Pull test
SAE J2707, Wear test procedure on inertia dynamometer for brake friction materials
SAE J2724, Measurement of disc brake friction material underlayer distribution
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
density
ρ
ratio of the mass to the volume of the friction material under normal conditions
3.2
porosity
P
relative volume proportion of cavities in a material
NOTE This includes open or enclosed pores of any size, shape and distribution.
4 Symbols and abbreviated terms
Symbol Definition Unit
ρ density g/cm
ρ absolute or real density without pore volume g/cm
net
m pad mass in air for density measurements g
a
m pad mass in water for density measurements g
w
V pad volume for density measurements cm
P porosity %
T room temperature °C
R
p brake pressure kPa
B
M torque Nm
d
W pad wear mm/g
B
W disc wear mm/g
s
µ coefficient of friction —
1) In preparation.
2 © ISO 2008 – All rights reserved

5 Product quality preplanning and test plan
5.1 General
The test requirements for the various phases are defined in the different test plans for passenger cars and
commercial vehicles in 5.4.
The development phase of prototypes (phases 1 to 4) describes the systematics and tests used in the
manufacture of brake linings from tools not yet meeting series standards. The end of phase 4 is the technical
product release.
The production transfer and initial sampling (phases 5 and 6) describes the required scope of testing for the
assessment of the initial production series with the tools and processes intended for the series.
The validation of the manufacturing process is proven by documentation and assessment of the results during
initial series production (phase 6).
The test volume during the continuing series production monitoring (phase 7) lies within the responsibility of
the pad manufacturer and is documented in the control plan (CP) which also includes the details for the
in-process inspection as well as for the incoming inspection of purchased parts like raw materials, backing
plates, shims and accessories.
Based on the level of in-process controls, the test efforts on the final product should be minimized and some
tests, such as friction tests, may not be needed for each single batch. In any case, the frequency and sample
size has to be defined in the CP.
The chemical-physical brake lining data of the tests listed below include performance and/or characteristic
data which result from a process chain. Any requirements of process capability indices and statistical process
control need to be agreed between the customer and the supplier. Agreed tolerances, however, have to be
respected.
5.2 Procedure
5.2.1 General procedure
The approval of brake linings is made by vehicle testing and a concurrent determination of its properties by
the test standards listed here.
The manufacturer of brake linings ensures that the parameters, the composition
...