1990 Pontiac Firebird Brake Service (ONLINE REPAIR MANUALS)

• Grease or any other foreign material must be kept off the brake linings, caliper, surfaces of the disc and external surfaces of the hub, during service procedures. Handling the brake disc and caliper should be done in a way to avoid deformation of the disc and nicking or scratching brake linings.
• If inspection reveals rubber piston seals are worn or damaged, they should be replaced immediately.
• During removal and installation of a wheel assembly, exercise care so as not to interfer...

This rear caliper, Fig. , consists of a single piston and an aluminum housing which is suspended in a mounting bracket through two slide pins. Hydraulic pressure, created by applying force to the brake pedal, acts equally against the piston and the bottom of the caliper bore to move the piston outward. This action slides the caliper inward, resulting in a clamping action on the brake rotor. This clamping act...

When working on or around brake assemblies, care must be taken to prevent breathing asbestos dust, as many manufacturers incorporate asbestos fibers in the production of brake linings. During routine service operations the amount of asbestos dust from brake lining wear is at a low level due to a chemical breakdown during use, and a few precautions will minimize exposure.

• Do not sand or grind brake linings unless suitable local exhaust ventilation equipment is used to prevent excessive asbestos exposure.
• Wear a suitable respirator approved for asbestos dust use during all repai...

COMPOSITE TYPE

Refer toFigs. and when performing the following procedures.

EXCEPT CORVETTE

Disassembly

• Remove master cylinder from vehicle as follows:
• Disconnect and plug hydraulic lines.
• Remove two master cylinder attaching nuts, then the master cylinder.
• Remove reservoir cover and diaphragm. Discard old brake fluid in reservoir.
• Inspect cover and diaphragm. Replace if cut, cracked or deformed.
• Remove fluid level switch, if equipped.
• On models with compact master cylinder, remove proportioner valve assembly,Fig. .
• Depress primary piston and remove lock ring.
• Plug primary fluid ou...

• Raise and support rear of vehicle, then remove tire and wheel assembly.
• Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. Refer to individual car chapter for procedure.If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap axle flange to drum mounting surface with a suitable hammer.
• Using brake spring pliers or equivalent, unhook primary and secondary return springs,Figs. and . Observe location of brake parts being removed to aid during installation.
• Remove brake hold-down springs with suitab...

Remove wheels and inspect brake disc, caliper and linings. The wheel bearings should be inspected at this time and repacked if necessary. Do not get any grease on the linings.

Do not replace individual pads or replace pads on one wheel of an axle set alone, as braking performance will be adversely affected.

If a visual inspection does not ade...