2005 Chevrolet Express 3500 Brake Service (ONLINE REPAIR MANUALS)

Removal

• Siphon ^2/3 of the brake fluid from master cylinder.
• Raise and support vehicle.
• Remove tire and wheel assembly.
• Compress caliper pistons until they bottom in bores using suitable clamp, Fig. .
• Disconnect brake hose at caliper by removing inlet fitting bolt.
• Remove mounting bolts and caliper.

Inspection

Should it become required to remove the caliper for installation of new components, clean components in denatured alcohol, wipe dry using lint-free cloths. Blow out drilled passages and holes using compressed air. Inspect dust boots for punctures or tears. If punctures or tears are...

Master Cylinder

Some vehicles use a conventional tandem master cylinder with two hydraulic pistons operating in-line. The primary piston controls the front brake system and the secondary piston controls the rear brake system.

Other models use a master cylinder that operates the same as the conventional master cylinder, but also incorporates a quick take-up feature in the rear chamber to reduce excessive pedal travel which may result from increased fluid displacement required to move the low drag caliper piston out against the rotor.

The quick take-up uses a spring-loaded ball check val...

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 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 thickness v...

Excessive Pedal Travel

• Worn brake linings.
• Disc pads knock back after cornering or rough road travel.
• Piston and linings not properly seated or positioned.
• Insufficient fluid in system.
• Loose wheel bearing adjustment.
• Damaged or worn caliper piston seal.
• Improper booster pushrod adjustment.
• Pads out of flat more than .005 inch.
• Rear brake automatic adjusters inoperative.
• Improperly ground rear brake shoes.

Brake Roughness Or Chatter; Pedal Pumping

• Excessive lateral runout of rotor.
• Rotor excessively out of parallel.

Excessive Pedal Effort

• Frozen or seized pistons.
• Brake fluid, oil or grease on ...

Brake System Bleed

Gravity and vacuum bleeding procedures are not recommended for use with the anti-lock brake system. The manual bleed procedure is the preferred method, although pressure bleeding is also possible. Do not pump the brake pedal during the bleeding process, as fluid aeration may occur.

Manual Bleed

• Raise and support vehicle, then connect a clear plastic tube to brake bleed screw at righthand rear wheel.
• Place free end of tube in a glass jar partially filled with clean brake fluid. Ensure end of tube remains submerged in fluid and master cylinder reservoir is kept full.
• ...

Manual Bleed

• If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off.
• Fill master cylinder reservoirs with suitable brake fluid. Ensure to always keep master cylinder reservoirs at least half full during entire bleeding procedure.
• If master cylinder is suspected to have air in bore, it must be bled first. To bleed master cylinder, proceed as follows:
• Disconnect forward brake pipe connection at master cylinder.
• Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port.
• Connect and ...