FRONT DISC BRK CALIPER BOLT BORE CORROSION

SUBJECT: FRONT DISC BRAKE CALIPER BOLT BORE CORROSION (REPLACE BOLT AND SLEEVE ASSEMBLY/BUSHINGS)

MODELS AFFECTED: 1990-92 SUNBIRD AND GRAND AM AND 1990-91 BONNEVILLE MODELS

THIS BULLETIN IS BEING REVISED TO CORRECT THE MODELS AFFECTED. THIS BULLETIN CANCELS AND REPLACES BULLETIN 92-5-6 ISSUED 11/91. PLEASE DISCARD BULLETIN 92-5-6.

CONDITION:

--------- Some 1990-92 Sunbird and Grand Am and 1990-91 Bonneville models may experience a condition of a caliper not sliding freely or moving on the mounting bolts inward toward the center of the vehicle.

CAUSE:

------ This condition is due to corrosion in the caliper mounting bolt area (See Figure 1) caused by contaminates seeping past the mounting bolt rubber bushing.

CORRECTION:

----------- Inspect the caliper suspension mounting bolts and sleeves for corrosion. Also, inspect the bushings for cuts, nicks and/or excessive wear. If damage to either part is found, replace with new parts.

IMPORTANT: Do Not attempt to polish away corrosion from the bolt or sleeve ---------- assemblies.

Lubricate the bushing bore with silicone grease, contained in Bushing Kit, P/N 18017226 or equivalent and install bolt and sleeve assembly. The bolt and sleeve assembly should slide through the bushing without the use of mechanical assistance. If the force required to slide the bolt and sleeve exceeds hand assembly pressure, remove the bushings and inspect the mounting bores for corrosion.

* If bores show signs of corrosion, clean the bores with a one inch wheel cylinder honing brush.

IMPORTANT: Replace rubber bushings with new parts contained in service kit, ---------- P/N 18017226 whenever they are removed from housing.

Parts are currently available from GMSPO.

Labor Operation Number: T1781 Labor Time : 1.2 Hours Trouble Code : 92

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.