1999 GMC C1500 Suburban Brake Service (ONLINE REPAIR MANUALS)

This system is used on all models except Montana, Silhouette, Tracker, Trans Sport and Venture. On 2000 S & T Series , four door utility vehicles can be equipped with either a 310 or 325 ABS system. Pickups and two-door utility vehicles are equipped with 310 ABS systems. While both systems are functionally the same, the 310 differs in size and appearance from the 325. It is designed to reduce the occurrence of wheel lock-up during severe braking conditions. To accomplish this function, the system regulates hydraulic brake line pressure by using an Electro-Hydraulic Control Unit (EHC...

2WD Models

Except Montana, Silhouette, Trans Sport & Venture

Front

• Raise and support vehicle.
• Remove tire and wheel assembly.
• Remove caliper as outlined under "Caliper Service."
• Remove grease cap from hub/rotor, Fig. .
• Remove cotter pin, nut and washer.
• Remove hub/rotor from spindle, being careful not to damage spindle threads or outer bearing.
• Reverse procedure to install, noting the following:
• Apply high-temperature wheel bearing grease to inner and outer wheel bearings.
• Torque nut to 12 ft. lbs. while turning wheel assembly forward by hand, back nut off one flat or until hole in spindle...

C & K Series

Duo-Servo

Removal

• Raise and support vehicle.
• Mark relationship of wheel to hub, then remove tire and wheel assembly.
• On models equipped with full-floating axles, remove hub and drum assembly as described in "Drive Axles."
• On models equipped with semi-floating axles, proceed as follows:
• Install pin into park brake lever.
• Mark relationship of drum to axle.
• Remove rear brake drum retainers, as required.
• Remove rear brake drum.
• On all models, remove return springs and shoe guide, Fig. .
• Remove brake hold down springs and pins.
• Disconnect actuator lever and pivot.
• Remove lever return spri...

Delco Master Cylinder

When performing the following procedures, refer to Figs. and noting that the composite reservoir may vary in design.

Disassemble

• Remove master cylinder from vehicle.
• 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 and proportioning valve assembly, if equipped.
• Depress primary piston and remove lock ring.
• Plug primary fluid outlet (outlet nearest to cowl when master cylinder is installed), then apply compressed air into secondary fluid outlet t...

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 ...

The caliper assembly slides on its mounting surfaces, Fig. . Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboar...