ISO 27667:2011

INTERNATIONAL ISO
STANDARD 27667
First edition
2011-07-15
Road vehicles — Brake lining friction
materials — Evaluation of corrosion effects
on painted backing plates and brake shoes
Véhicules routiers — Matériaux de friction pour garnitures de freins —
Évaluation des effets de la corrosion sur plateaux de freins peints et
segments de freins peints
Reference number
©
ISO 2011
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ii © ISO 2011 – 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 27667 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 2, Braking
systems and equipment.
Introduction
Corrosion issues and testing are varied and costly to assess, diagnose, and correct. This International
Standard is used in conjunction with other standards which provide specific test methods, description of sample
preparation and testing apparatus, evaluation criteria, and test reports. Emphasis is placed on the evaluation
methods to ensure a definite set of international standards for reporting the different phenomena observed
during and at the completion of testing.
This International Standard is intended for use in conjunction with other applicable standards or test procedures
(ASTM, ISO, SAE, JASO, and other project or company-specific testing programs) to fully assess a friction
material’s adequacy for use in a certain application, market or vehicle platform. This International Standard
does not include performance requirements related to durability, cosmetic appearance, or function under
different vehicle conditions of temperature, mechanical stresses, environments, contamination, and operating
conditions of the braking system as observed during actual vehicle operation.
Brake pads and brake shoes are key components in the vehicle braking system. Corrosion and its effects can
generate warranty issues or costly repairs during the life-cycle of the vehicle. Since brakes are part of the under-
body components, a detailed evaluation related to corrosion requires a comprehensive approach that provides
a uniform set of laboratory test procedures and assessment criteria. Since corrosion-related phenomena are
complex, this International Standard provides harmonization with other available international standards.
Previous experience in similar cases is a useful way to support the selection of a paint system for a specific
application. The brake pad or shoe lining durability under corrosive environments depends heavily on factors
such as working environment, system design, paint thickness and composition, surface preparation, application,
drying and handling. Of primary interest are the chemical and physical characteristics of the binder and the dry-
film thickness. Artificial-aging tests are useful to evaluate these characteristics. These tests include:
— resistance to moisture;
— resistance to fog;
— resistance to chemicals.
Exercise caution when analysing artificial-aging test results. Artificial exposure will not necessarily have the
same effect as natural exposure. Not all factors occurring on the vehicle application are able to accelerate or
replicate in the proper way. When feasible, plan and conduct natural-exposure or field-testing so that, in the
long term, such abnormalities are resolved.
Since there are no models widely accepted by the industry to predict in-service life based on laboratory
corrosion testing, estimation of actual durability for a given application or environment is beyond the scope of
this International Standard.
iv © ISO 2011 – All rights reserved

INTERNATIONAL STANDARD ISO 27667:2011(E)
Road vehicles — Brake lining friction materials — Evaluation of
corrosion effects on painted backing plates and brake shoes
1 Scope
This International Standard defines the methods for testing and assessing the corrosion effects on painted
backing plates used on disc brakes and painted brake shoes used on drum brakes.
The methods and assessment criteria indicated in this International Standard are part of the specification/validation
phases of the product and the series production monitoring from ISO 15484.
The test procedures indicated include only laboratory performance testing, whether static or cyclic. Field
surveys or proving grounds test protocols are beyond 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 2409, Paints and varnishes — Cross-cut test
ISO 2812-1, Paint and varnishes — Determination of resistance to liquids — Part 1: Immersion in liquids
other than water
ISO 4628-1, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size of
defects, and of intensity of uniform changes in appearance — Part 1: General introduction and designation system
ISO 4628-2, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size
of defects, and of intensity of uniform changes in appearance — Part 2: Assessment of degree of blistering
ISO 4628-3, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size
of defects, and of intensity of uniform changes in appearance — Part 3: Assessment of degree of rusting
ISO 4628-4, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity and size
of defects, and of intensity of uniform changes in appearance — Part 4: Assessment of degree of cracking
ISO 8044, Corrosion of metals and alloys — Basic terms and definitions
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 15484:2008, Road vehicles — Brake lining friction materials — Product definition and quality assurance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8044, ISO 15484 and the following apply.
3.1
atmospheric corrosion
corrosion process that takes place in a film of moisture on the metal surface
NOTE The moisture film may be invisible to the naked eye.
3.2
artificial aging
aging above room temperature to accelerate or change a certain condition on a component
3.3
chalking
development of loose removable powder a
...