Regulation No. 90-02 Proposed Supplement 3

Name:Regulation No. 90-02 Proposed Supplement 3
Description:Replacement Brake Lining Assemblies. Proposed Supplement 3 to the 02 Series.
Official Title:Proposal for Supplement 3 to the 02 Series of Amendments to Regulation No. 90 (Replacement Braking Parts).
Country:ECE - United Nations
Date of Issue:2016-04-06
Amendment Level:Original
Number of Pages:33
Information:Provisional Date of Entry into Force: February 9, 2017
Vehicle Types:Bus, Car, Component, Heavy Truck, Light Truck, Motorcycle, Trailer
Subject Categories:Drafts and Proposals (Historical)
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Keywords:

brake, disc, test, paragraph, vehicle, discs, braking, surface, annex, replacement, read, part, original, categories, regulation, table, diameter, amend, group, material, carried, type, tests, figure, dynamometer, paragraphs, case, maximum, properties, add, wheel, speed, mass, performance, drum, max, inertia, holes, friction, dynamic, thickness, approval, bell, vehicles, requirements, fatigue, pursuant, values, front, testing

Text Extract:

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ECE/TRANS/WP.29/2016/58
PROPOSAL FOR SUPPLEMENT 3 TO THE 02 SERIES OF
AMENDMENTS TO
REGULATION NO. 90
(REPLACEMENT BRAKING PARTS)
ADOPTED AT THE 169 SESSION – JUNE 2016
PROVISIONAL DATE OF ENTRY INTO FORCE: FEBRUARY 9, 2017

Renumber former Paragraph 2.3.3.4. as 2.3.3.4.1. and amend to read:
"2.3.3.4.1. "Equivalent brake discs for Categories M, N and O" is a replacement brake disc which
is identical to the original brake disc in respect to all dimensions, geometric features and
basic design and is also from the same material subgroup as the original brake disc as
defined in Paragraph 5.3.3.2."
Add a new Paragraph 2.3.3.4.2., to read:
"2.3.3.4.2. "Equivalent brake discs for Categories L , L , L , L and L " are replacement brake
discs which are identical to the original brake disc in respect to all dimensions, geometric
features and basic design and is also from the same following materials:
(a) Braking surface: one of materials listed in Paragraph 5.3.3.2.2;
(b)
Bell and braking ring fasteners: same materials and mechanical properties of
original disc"
Renumber former Paragraph 2.3.3.5. as 2.3.3.4.3.
Add a new Paragraph 2.3.3.5., to read:
"2.3.3.5. Interchangeable brake discs and brake drums"
Renumber Paragraph 2.3.3.6. as 2.3.3.5.1.
Renumber Paragraph 2.3.3.7. as 2.3.3.5.2.
Paragraph 3.4.1.1., amend to read:
"3.4.1.1. Disc or drum drawing(s) … accessories:
(a)
(b)
(c)


Material (for one piece discs) or material for composed and floating disc of
Categories L , L , L , L and L ."

Paragraph 3.4.3.1., amend to read:
"3.4.3.1. A minimum number of disc or drum samples – of the design for which approval is
requested – shall be provided, as shown in the following table.
The table also shows the recommended use of the samples.
Item
No.
Check/Test
Sample number for brake discs for
vehicles of Categories M, N and O
1 2 3 4 5 6
1 Geometric check Paragraphs 5.3.3.1., 5.3.4.1. x x x x x x
2 Material check Paragraphs 5.3.3.2. x x
3 Balancing provisions check Paragraph 5.3.7.2. x x x x
4
5
6
7
8
9
Wear condition marking check
Paragraph 5.3.7.3.
Integrity test − thermal fatigue Paragraphs
4.1.1., 4.2.1. of Annex 11, 4.1.1., 4.2.1. of
Annex 12
Integrity test − high load test
Paragraphs 4.1.2., 4.2.2. of Annex 11, and
Paragraphs 4.1.2., 4.2.2. of Annex 12
Service brake vehicle performance test
Paragraph 2.2. of Annex 11, Paragraph 2.2. of
Annex 12
Parking brake vehicle performance test
Paragraph 2.3. of Annex 11, Paragraph 2.3. of
Annex 12
Service brake dynamometer performance test
Paragraph 3.3. of Annex 11, Paragraph 3.3. of
Annex 12
x x x x
x
x
x
Pair of
discs
Pair of
discs
x
Remarks
Either front
or rear axle
If applicable
Alternative
to vehicle
test

Paragraph 5.3., amend to read:
"5.3. Technical Requirements…

Depending on its group, the replacement brake disc or drum has to pass the following
tests:
Resistance to
static torque (only
for Vehicle
Categories L , L ,
L , L and L )
Performance tests
according to
Regulations Nos.
13/13-H/78 (Type
0, I, II, etc.)
Comparison test
with dynamic
frictional
properties of the
original part
Integrity tests
(high load and
thermal fatigue)
Original
replacement parts
Disc not
subjected to this
regulation
Identical parts No No No No
Equivalent parts No No No
Dynamometer
test
Interchangeable
parts
Static bench test
Vehicle test or
alternative
dynamometer test
Vehicle test or
alternative
dynamometer test
Dynamometer
test
The test requirements for brake discs and drums for vehicles of Categories M and N are
detailed in Annex 11.
The test requirements for brake discs and drums for vehicles of Category O are detailed
in Annex 12.
The test requirements for brake discs for vehicles of Categories L , L , L , L and L are
detailed in Annex 14."
Paragraph 4.2.3., amend to read:
"4.2.3. The next series of digits shall indicate the manufacture and the type of the brake lining,
the type of disc or the type of drum.
The digital suffix shall indicate:
(a)
(b)
The shoe or back plate or specific dimension in the case of drum brake linings;
The Test Group in the case of a replacement disc or replacement drum.

Paragraph 5.3.3.1.1., amend to read:
"5.3.3.1.1.
For discs the following maximum values shall be met:
M , N , O , O
M , M , N , N , O , O
L , L , L , L , L
Thickness variation
0.015mm
0.030mm
0.020mm
Cheek thickness variation
(for ventilated disc only)
1.5mm
2.0mm
Lateral run-out friction surface
0.050mm*
0.150mm*
0.150mm
Location bore variation
H9
H9
D10 or H11
"Top hat" parallelism
0.100mm
0.100mm

Location face flatness
0.050mm
0.050mm
0.100mm
Friction surface roughness**
3.2μm
3.2μm
1.6μm
"
Add a new Paragraph 5.3.3.2.1., to read:
"5.3.3.2.1. For vehicles of Category M, N, O, in order to be considered "Equivalent" the replacement
brake disc or drum shall be from the same material sub-group as the original brake disc
or drum. Four original part material sub-groups are defined."

Paragraph 5.3.5.1.2., amend to read:
"5.3.5.1.2. Material group
For brake discs for vehicles of Categories M, N and O, all material groups (including their
respective subgroups) are considered to be a separate type.
For brake discs for vehicles of Categories L , L , L , L and L , all material groups
(excluding the martensitic stainless steel subgroup) are considered to be a separate
type."
Paragraph 5.3.6., amend to read:
"5.3.6. Test Group Criteria (Within the Same Type)
It is only possible to test interchangeable parts in Test Groups if the connection between
the mounting area and the disc friction faces are of the same general form….
….
With:
V maximum design speed of the vehicle to which the
replacement part is fitted (in the case of trailers v is
assumed at least at 80km/h)
m test mass as defined in Annex 11, Paragraph 3.2.1.2.,
Annex 12, Paragraph 3.2.1.2. and Annex 14,
Paragraph 4.2.1.2.
m mass of the replacement part" of the corresponding vehicle"
Add new Paragraphs 5.3.6.1.3. and 5.3.6.1.3.1., to read:
"5.3.6.1.3. Criteria concerning the formation of test groups with regard to replacement brake discs in
vehicles belonging to Categories L , L , L , L and L .
5.3.6.1.3.1. Test group relating to the tests stipulated of Annex 14.
This test group includes all brake discs according to the criteria set out in Annex 15."
Paragraph 5.3.7.4., amend to read:
"5.3.7.4. Tests
Each test group (see Paragraph 5.3.6.) within a particular type of replacement brake
disc/drum (see Paragraph 5.3.5.) shall be tested by the Technical Service."

Annex 9,
Title of Part B, amend to read:
"PART B:
CONFORMITY OF PRODUCTION FOR BRAKE DISCS AND DRUMS IN CAST IRON"
Add Part C, to read:
"PART C:
CONFORMITY OF PRODUCTION FOR BRAKE DISCS IN MARTENSITIC STAINLESS STEEL
1. INTRODUCTION
Part C applies to replacement brake discs approved to this Regulation.
2. REQUIREMENTS
Conformity of production is to be demonstrated through the routine control and
documentation of at least the following:
2.1. Chemical Composition
2.2. Mechanical Properties
Rockwell C hardness measured in accordance with ISO 6508-1:2005.
In each case the measurements must be made on samples taken from the actual brake
disc or drum.
2.3. Geometric Features
Brake Discs:
(a)
(b)
(c)
Thickness variation;
Friction surface run out;
Friction surface roughness.

Add a new Paragraph 3., to read:
"3. BRAKE DISC DESIGN TYPES FOR L , L , L , L AND L CATEGORIES (EXAMPLES)
One-piece type: brake disc with braking surface and bell made in a single piece and,
therefore, of the same material
Composed fixed type: brake disc having the braking ring made of steel, while the bell is
of other material, generally aluminium; the 2 components are rigidly bounded by a
screwed or riveted connection.
Floating type: brake disc having the braking ring radially released from the bell, in order
to allow its thermal expansion.

Table A14/1.
Static bench
test
Vehicle test
Alternative dynamometer test
Resistance to static torque test 2. – –
Performance tests according to
Regulation No. 78
– 3.2.3. Dry stop test 4.4.1. Dry stop test
3.2.4. Wet brake test –
3.2.5. Heat fade test 4.4.2. Heat fade test
Comparison test with original part
Integrity test
– 3.2.6. Testing the dynamic
frictional properties
– No vehicle test − use
dynamometer test
4.4.3. Testing the dynamic
frictional properties
5.1. Brake disc thermal fatigue
test
For each disc type, at least one test group (see definition in Paragraph 5.3.6. of this
Regulation) requires the "Dry stop", "Wet brake" and "Heat fade" tests to be carried out
on a vehicle.
2. STATIC BENCH TEST REQUIREMENTS
2.1. Purpose
To verify the resistance of the bell and, in case of floating discs, of the connection
system to the braking ring when the disc is subjected to a braking torque.
2.2. Test Procedure and Conditions
Static test performed on special test bench shown in Figure 1.
Figure 1

Figure 2
Movement
Where:
(a)
(b)
(c)
(d)
(e)
Adjustment stroke of the equipment (recovery of any clearance between the hole
on the braking surface and the connection pin to the bench arm);
Load developed by the fastening screws to the equipment;
Movement of the brake disc caused by its rotation with sliding on the plate of the
equipment, when the disc’s fastening screws bear against the fixing holes of the
disc;
Load supported by the brake disc;
Permanent deformation of the brake disc (starting from point A).
2.3. Test Results
The disc shall not permanent deformations before reaching the force F specified in
Table A14/2.2.5; the measurement of the deformation force must be performed at
Point A as in Figure 2.

3.2.6. Testing the Dynamic Frictional Properties (comparison test conducted on the individual
wheel)
For this test, the vehicle shall be laden and all brake applications carried out on a flat
road with the engine disconnected.
The service braking system of the vehicle shall be provided with a device that separates
the front-wheel brake from the rear-wheel brake so that they can always be operated
independently of one another.
If an approval or a part report is required in connection with a replacement brake disc for
the front-wheel brake, the rear-wheel brakes shall remain inoperative throughout the test.
If an approval or a part report is required in connection with a replacement brake disc for
the rear-wheel brake, the front-wheel brake shall remain inoperative throughout the test.
3.2.6.1. Performance Comparison Test when the Brakes are Cold
With cold brakes, the performance of the replacement brake disc shall be compared with
the original equivalent by comparing the results of the test below.
3.2.6.2. Using the replacement brake disc, at least six consecutive brake applications with
different, gradually increasing control forces or brake pressures are carried out as part of
the process up to the point at which the wheel lock, or up to a mean fully developed
deceleration of 6m/s or up to the maximum control force or line pressure permitted for
this category of vehicle, in which connection the initial speed for the testing of front or
rear wheel brake disc is as per the table below:
Vehicle Category
Table A14/3.2.6.2.
Test speed in km/h
Front wheel
Rear wheel
L , L 30 30
L , L , L , 70 45
Prior to each brake application, the initial temperature of the brake disc shall be ≤ 80°C.
3.2.6.3. The brake test described in Paragraph 3.2.6.2. also has to be carried out using the
original brake disc.
3.2.6.4. The dynamic frictional properties of the replacement brake disc can be regarded as
similar to those of the original brake disc, provided the values attained in relation to the
mean fully developed deceleration at the same operating pressures or control forces in
the region of the upper 2/3 of the curve generated do not deviate by either ±15% or
±0.4m/s from those of the original brake disc (see an example of the curve in Figures 3
and 4).

4. INERTIA DYNAMOMETER TEST
4.1. Equipping the Dynamometer
For testing purposes, the dynamometer shall be fitted out with the original brake caliper.
The inertia dynamometer shall be equipped with a constant torque device and equipment
for recording rotational speed, brake pressure, the number of revolutions after braking
has commenced, brake torque, the braking period and the temperature of the brake
discs on a continuous basis.
4.2. Test Conditions
4.2.1. Inertia Mass of the inertia Dynamometer
The inertia mass of the inertia dynamometer shall be set as close as possible, with a
permissible variation of ±5%, to the theoretically required value which corresponds to
that part of the total inertia of the vehicle braked by the appropriate wheel. The formula
used for calculation purposes is as follows:
Where:
I = rotary inertia (kgm );
I = m ⋅ r
r = dynamic rolling radius of the tyre (m);
m
=
test mass (part of the maximum mass of the vehicle braked by the
appropriate wheel) as stipulated by this Regulation.
4.2.1.1. Dynamic Rolling Radius
In calculating the inertia mass, the dynamic rolling radius (r
authorised for the vehicle shall be taken into account.
) of the largest tyre
4.2.1.2. Test Mass
The test mass for calculating the inertia mass shall be as follows:
(a)
When testing front wheel brake disc:
m = x · m m = max. permitted mass of the vehicle
(b)
When testing rear wheel brake disc:
m = y · m m = max. permitted mass of the vehicle

4.4.3. Testing the Dynamic Frictional Properties
With cold brakes, the performance of the replacement brake disc shall be compared with
the original equivalent by comparing the results of the test below.
4.4.3.1. Using the replacement brake disc, at least six consecutive brake applications with
different, gradually increasing control forces or brake pressures are carried out as part of
the process up to a mean fully developed deceleration of 6m/s . The maximum control
force or line pressure have not to exceed the maximum allowed control forces or line
pressure permitted for this category of vehicle, in which connection the initial speed for
the testing of front or rear wheel brake disc is as per the table below:
Table A14/4.4.3.1.
Vehicle Category
L
L
L
L
L
Test speed in km/h
Front wheel
Rear wheel
30
30
70
45
Prior to each brake application, the initial temperature of the brake disc shall be ≤ 80°C.
4.4.3.2. The brake test described in Paragraph 4.4.3.1. also shall be carried out using the original
brake disc.
4.4.3.3. The dynamic frictional properties of the replacement brake disc can be regarded as
similar to those of the original brake disc, provided the values attained in relation to the
mean fully developed deceleration at the same operating pressures or control forces in
the region of the upper 2/3 of the curve generated do not deviate by either ±15% or
±0.4m/s² from those of the original brake disc (see an example of the curve in
Figure 3 and Figure 4 of Annex 14).
5. INTEGRITY TEST USING AN INERTIA DYNAMOMETER
The tests are conducted in accordance with Paragraph 5.1. (discs).
A single test per test group is required unless the replacement part does not achieve the
required number of cycles before damage or failure (see Paragraph 5.1.1.1.3. or
5.1.1.2.3. of this Annex).
The brake should be installed on the dynamometer in accordance with its fitting position
on the vehicle (rigidly mounted brake or this installed by means of a stub axle are
exempt).
The temperature of the brake disc should be measured in as close proximity to the
friction rubbing surface as possible. The temperature measurement should be recorded
and the method and measuring point shall be the same for all tests.

5.1.3.1.2. Fatigue test
According to Table A14/5.1.3.1.2.
Table A14/5.1.3.1.2.
5.1.4. Rear Disc
5.1.4.1. Test program
5.1.4.1.1. Burnishing
According to Table A14/5.1.4.1.1.
Table A14/5.1.4.1.1.

5.1.5. Test Result (Brake Disc Thermal Fatigue Test)
The test is regarded as having been passed if the cycles prescribed in:
(a)
(b)
Tables A14/5.1.3.1.1. – 5.1.3.1.2. for front discs
Tables A14/5.1.4.1.1. – 5.1.4.1.2. - 5.1.4.1.3. for rear discs are completed without
damage or failure.
If less than 20 cycles, according to "Thermomechanical Fatigue test" in
Tables A14/5.1.3.1.2. and A14/5.1.4.1.3., but more than 15 are completed without
damage or failure, then the test must be repeated on a new replacement part.
Under these circumstances both tests must complete more than 15 cycles without
damage or failure for the part to have passed the test.
If less than 15 cycles are completed before damage or failure, then a test should be
conducted on the original part and the results compared.
If the damage of failure point is no worse than the quantity of cycles of the original part –
10%, then the test is regarded as having been passed.
Damage or failure, in this context, means:
5.1.5.1. During the Test:
5.1.5.2. After the Test:
Temperature exceeds 600°C.
(a)
(b)
(c)
(d)
(e)
(f)
Contact between caliper and disc;
Cracks, permanent deformation or breakings;
Abnormal wear;
A 0.150mm maximum increasing of run-out, compared to the initial value
measured before the test, is allowed;
A 0.250mm maximum run-out is allowed;
A 0.100mm maximum (for "full floating" disc) straightness increasing, compared to
the initial value measured before the test, is allowed."

Figure 3 Figure 4
2. GROUPS OF DISCS
"Group of discs" means a grouping of similar discs, so that the tests performed on a
single disc are considered valid for the entire group of similar discs.
Discs belonging to the same group must have following features, as indicated at
following Paragraphs from 2.1. to 2.9.
For a given group of discs, the approval tests may be performed on one disc, belonging
to the group, subjected to the highest braking torque and to the largest energy to be
absorbed.
The similarity between the discs is defined by following grouping criteria, that must be
simultaneously fulfilled:
2.1. Same type of the reference disc for that group (one piece, composed fixed or floating).
2.2. Braking surface material to be chosen among those listed at Paragraph 5.3.3.2.2.; other
materials can be used provided that, under approval, they are declared with equal
demonstration of test results according to Paragraph 8. In this case, the extension
applies to all groups listed in Table 3 for dimensions equal or lower to that demonstrated.
2.3. Braking surface lightening: any solution is allowed (holes, slots, wave, etc.) provided
that:
2.3.1. For discs having the same diameter and thickness: the mass change of the braking
surface swept by the pads must be within the range of ±20% with respect to the
reference disc.

2.5. Same material and mechanical properties, as specified in the international standard for
materials, or higher, for the bell/braking surface fasteners.
2.6. Spokes of the bell with full/empty ratio – measured on the average circumference
between end of the mounting face and beginning of the braking surface – within the
range ±20%, thickness within the range (+30%) ÷ (–10%) and same mechanical
properties, as specified in the international standard for materials, with respect to the
reference disc.
2.7. Same technical solution for the bell-braking surface fasteners (same drawing and
materials; for the quantity of bell-braking surface fasteners, permitted the same quantity
with a tolerance of +2 –0).
2.8. The quantity of fixing holes is not binding by group belonging, in order to ensure
interchangeability with original disc.
2.9. Outer diameter included in the range of 50mm, according to Table 2.9.:
Table A15/2.9.
Range [mm] One piece Composite fixed Floating discs
≥ 150 < 200 X X X
≥ 200 < 250 X X X
≥ 250 < 300 X X X
≥ 300 < 350 X X X
There are no groups for "peripheral" discs (fitted on the wheel outer diameter).
Note:
For new applications that will be included into an existing group, an increase of 10%
maximum kinetic energy is allowed with reference to the value used for the approval of
the disc of the reference group.
Data for the new calculation of kinetic energy must be traced from the product data sheet
issued by the vehicle manufacturer.
In the case of discs with applications on both wheels, front and rear, the approval tests at
Paragraph 8. shall be conducted on heaviest application."
Replacement Brake Lining Assemblies. Proposed Supplement 3 to the 02 Series.