Brake Pad/Caliper/Knuckle - Inspect & Maintenance
File In Section: 5 - BrakesBulletin No.: 63-50-19
Date: January, 1997
INFORMATION
Subject:
Inspection/Maintenance Procedure for Restricted Movement
between Brake Pad and Caliper and/or Knuckle
Models:
1990.5 Buick Electra
1991-1996 Buick Park Avenue
1991-1997 Buick LeSabre, Skylark
1990-1992 Cadillac Fleetwood
1990-1996 Cadillac DeVille
1992 Cadillac Sixty Special
1992-1996 Cadillac Eldorado, Seville
1994-1996 Cadillac Concours
1992-1996 Chevrolet Beretta, Cavalier, Corsica, Lumina APV
1993.5-1997 Chevrolet Camaro
1997 Chevrolet Malibu
1990.5-1996 Oldsmobile Ninety Eight
1991 Oldsmobile Calais
1991-1997 Oldsmobile Eighty Eight
1992 Oldsmobile Toronado
1992-1996 Oldsmobile Silhouette
1992-1997 Oldsmobile Achieva
1996-1997 Oldsmobile LSS, Regency
1997 Oldsmobile Cutlass
1991-1997 Pontiac Bonneville, Grand Am
1992-1994 Pontiac Sunbird
1992-1996 Pontiac Trans Sport
1993.5-1997 Pontiac Firebird
1995-1996 Pontiac Sunfire
Customer Service Notes
Your customers should be made aware of the maintenance requirements of their vehicle. These owner responsibilities are described and listed in the Owner's Manual under Periodic Maintenance Inspections. (Example: brake linings, Tire and Wheel Inspection and Rotation are owner maintenance.)
Some of the above listed vehicles may exhibit restricted movement between the brake pad and the caliper and/or knuckle.
Movement may be restricted by:
a. Debris, build-up, or
b. Corrosion
If the pads do not have free movement within the caliper and/or knuckle, one or both pad(s) may remain against the rotor. This may lead to the following:
a. Early pad wear-out
b. Rotor thickness variation (may result in pulsation)
c. Rotor damage it not corrected in time.
The following procedure should be used to inspect for and correct restricted pad movement:
Inspection
1. Move wheel and tire from vehicle.
2. Move the piston into the caliper bore using a C-clamp (Kent-Moore tool # J 42588 or equivalent). Refer to Figure 1.
Notice:
Use care to avoid permanently bending the anti-rattle clips on the outboard brake pad, 5 mm (1/8 inch) is sufficient.
3. Check the outer brake pad for freedom of movement relative to the knuckle abutment. Refer to Figure 2.
Important:
The brake pads must move easily within the knuckle.
4. Using hands, push the caliper in as far as possible. The lining should retract with the piston/caliper housing. Refer to Figure 3.
5. Check the inner brake pad for freedom of movement relative to the knuckle abutment. Refer to Figure 3.
6. Repeat this procedure for the other side of the vehicle.
7. If all pads move freely, go to Step # 7 under "Correction" and install the wheels and tires. If movement is restricted, proceed with Step # 1 under "Correction."
Correction
If restricted pad movement is noted on one or more calipers, perform the following "clean and lubricate" procedure.
1. Remove the brake pads from the caliper.
2. Remove all debris and corrosion from the knuckle using a wire brush at any points where the brake pads come in contact with the knuckle and/or caliper. If the corrosion is severe, use a scraper first. Refer to Figure 4.
3. Using a wire brush/scraper, remove all debris and corrosion from the brake pad metal backing shoe in the areas where the shoes contact the knuckle and/or the caliper. Refer to Figures 2 and 3.
4. Coat all areas of the knuckle and/or caliper where the brake pad shoes contact using a high temperature silicone grease, P/N 18010909 or equivalent. Refer to Figure 4.
5. Install the brake pads and caliper on the vehicle.
6. Repeat Steps 1 - 5 on the other caliper brake assembly. If one caliper needs service, do both sides.
7. Reinstall wheels and tires on the vehicle.
Important:
Evenly torque wheel nuts to specification using a torque wrench or a torque limiting socket/stick.
A torque wrench or torque stick must be used to insure that wheel nuts are tightened to specification. This should be done in three steps using the star pattern. First, snug the nuts down by hand. Second, using the star pattern and a torque stick/wrench, tighten the wheel nuts to about half the final torque. Third, tighten the wheel nuts to specification using the star pattern and a torque stick/wrench. Use the same amount of impact wrench operating time as would normally be used without a torque stick.
8. Pump the brake pedal as many times as required to obtain a firm brake pedal.
Caution:
DO NOT move the vehicle until a firm brake pedal is obtained. Failure to obtain a firm brake pedal before moving vehicle may result in personal injury.
Parts Information
Parts are currently available from GMSPO.