Brake Pads - Minimizing Brake Noise
NUMBER202
GROUP
51
MODEL
200
TITLE
BRAKE PADS
200 ALL
MARKET
US and Canada
DATE
April 1993
THIS BULLETIN SUPERSEDES SB 51-14; DATED 05/88
REFERENCE:
TP 11485/4 (ENGLISH); 06/88; BRAKES, 240, 260
TP 31678/1 (ENGLISH); 09/90; ANTI-LOCK BRAKING SYSTEM (ABS) 200
Brake pads
This bulletin provides a list of all brake pads currently in use and instructions for minimizing brake noise.
Current front and rear brake pad kits for 200 series
The table shows the front and rear brake pads which are currently used on the 200 series and which are available as replacement parts.
Replace brake pads when the friction material reaches a minimum thickness of 3 mm at the front and 2 mm at the rear, or if it is considered that the wear will exceed permissible limits before the next service.
Note:
Measure the thickness of the brake discs whenever replacing pads. The discs must also be replaced if the measured thickness is less than the minimum permissible value.
Note:
Apply silicone grease, p/n 1161325-4, to both sides of anti-squeal shim.
Only this grease may be used when working on brakes since other types may contain mineral oil which will damage rubber braking system components.
Apply a thin layer of silicone grease to other contact surfaces (i.e. pins and the brake pad backing plate edges). Do not apply too much silicone grease; excessive grease may contaminate friction surfaces.
Note:
When installing brake pads in caliper: Put shop cloth over master cylinder cap. Press back brake pistons slowly and carefully with universal pliers until rubber dust seals are slightly below piston ends, ensuring that seals cannot be damaged by brake pad backing plates during installation.
Measurement of brake disc thickness
Note:
Brake discs should be replaced in pairs.
Depending on the driving style of the owner, an assessment must be made in each individual case as to whether the brake pads and discs should be replaced, to ensure that the thickness of either is not less than the minimum permissible value before the next service.
Action to minimize brake noise
Front brakes
A rubber-coated anti-squeal shim, p/n 1359198-7, may be installed between the brake piston and brake pad backing plate to minimize brake noise such as squealing, screeching or "tuning fork". Grease both sides of the shim with a thin coating (approx. 0.1-0.2 mm) of silicone grease, p/n 1161325-4, prior to installation.
Note:
Anti-squeal shims are included in the Girling front brake pad kit.
It is essential to clean the brake caliper thoroughly when replacing brake pads and/or installing anti-squeal shims. A steel brush may be used, leaving the shim in position to protect the piston dust seals.
This applies generally to both front and rear brakes.
Rear brakes
ATE
Anti-squeal shims should be installed in the following sequence (see illustration) to minimize brake noise such as squealing or screeching:
A in illustration: Anti-squeal shims of stainless steel, p/n 1359772-9, should be installed on the piston side of the caliper (two per caliper).
B in illustration: Rubber-coated anti-squeal shims, p/n 1228590-4, should be installed on the brake pad backing side (two per caliper). These shims should be lubricated on both sides with a thin coating (approx. 0.1-0.2 mm) of silicone grease, p/n 1161325-4.
Note:
Anti-squeal shims are included in the ATE rear brake pad kit.
C in illustration: Brake pad backing plate
Girling
This type of caliper is equipped with a brake piston with an integral washer at the piston end, which functions as an anti-squeal shim. If noise conditions are encountered, coat the brake pad backing plate with silicone grease.
"tuning fork" noise
Install bracket (D in illustration) with rubber pad, p/n 54244-9, as follows:
Insert rubber block in bracket. Remove upper mounting bolt of handbrake anchor plate. Install bracket using new mounting bolts. Tighten 50 N-m (37 ft.lbs.).
The rubber block has been factory-installed on the following chassis numbers:
244: 176566-429800 and 483230-
245: 678008-883200 and 948657-
WARRANTY STATEMENT:
Claims may be submitted under the New Car Limited Warranty when a manufacturing defect is present using claim type: 01.
Note:
Brake noise is normally not covered under warranty.