1995 GMC C3500 Pickup Brake Service (ONLINE REPAIR MANUALS)

Brake System Bleed

1992

Before bleeding the brakes, the front and rear displacement cylinder pistons must be returned to the top most position. Using a TECH 1 or equivalent scan tool, enter manual control function and apply the front and rear motors. Ensure enable relay is on.

Use only DOT 3 brake fluid from a clean and sealed container. Do not use DOT 5 brake fluid.

Pressure Bleeding

• Remove master cylinder cover, ensure reservoir is properly filled.
• Connect bleeder adapter tool No. J 35589, or equivalent, to master cylinder reservoir.
• Connect bleeder adapter to pressure bleeding equipm...

Height Sensing Proportioning Valve

The height sensing proportioning valve must be adjusted whenever the valve and/or linkage is disassembled or removed for service. In addition, adjustment should be checked if excessive front wheel lock-up is experienced with a lower than desired brake application rate when vehicle is at or near maximum GVWR.

• Raise and support vehicle leaving wheels on, and allow axle to hang freely.
• Remove lever retaining nut and disconnect lever from valve shaft, Fig. .
• Rotate valve shaft to permit installation of correct adjustment gauge, Fig. , ensuring that D shape...

Removal

• Siphon ^2/3 of brake fluid from master cylinder reservoir serving front disc brakes.
• Raise vehicle, support on jack stands and remove front wheels.
• Bottom caliper piston in bore. Insert a screwdriver between inboard shoe and piston, then pry piston back into bore. The piston can also be bottomed in the bore with a large C-clamp, Fig. .
• Remove support key retaining screw.
• Drive caliper support key and spring from steering knuckle with a suitable drift and hammer, Fig. .
• Lift caliper from anchor plate and off rotor, Fig. . Hang caliper from coil spring with wire. Do not allow cal...

Brake Lines & Linings

Remove one of the front wheels and inspect the brake disc, caliper and linings.

Do not allow any oil or grease on the linings. It is recommended that all linings be replaced in sets when worn or damaged.

If the caliper is cracked or fluid leakage through the casting is evident, it must be replaced as a unit.

Brake Roughness

The most common cause of brake chatter on disc brakes is a variation in thickness of the disc. If roughness or vibration is encountered during highway operation or if pedal pumping is experienced at low speeds, the disc may have excessive thickne...

The braking system can be bled manually or with pressure bleeding equipment. If bleeding manually, check fluid level frequently.

Brake fluid should never be reused. Before driving the vehicle, check brake operation to ensure a firm pedal has been obtained.

Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always seal and wipe off brake fluid containers to prevent spills.

Manual Bleeding

C/K, G, M/L, P & S/T Series

• If vehicle is equipped with a vacuum or hy...

The Bendix single piston sliding caliper disc brake is standard equipment on some truck applications, while on other trucks it is used only in Hydro-Boost power brake applications with both front disc brakes and 4 wheel disc brakes. On 4 wheel disc brakes, the front and rear systems are identical.

T...