1991 Ford F-350 Pickup Brake Service (ONLINE REPAIR MANUALS)

EXCESSIVE PEDAL TRAVEL

• Worn brake lining.
• Shoe and lining knock back after cornering or rough road travel.
• Piston and shoe and lining assembly not properly seated or positioned.
• Air leak or insufficient fluid in system or caliper.
• Loose wheel bearing adjustment.
• Damaged or worn caliper piston seal.
• Improper booster pushrod adjustment.
• Shoe out of flat more than .005 inch.
• Rear brake automatic adjusters inoperative.
• Improperly ground rear brake shoe and lining assemblies.

BRAKE ROUGHNESS OR CHATTER; PEDAL PUMPING

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

EXCESSIVE P...

This brake booster is a hydraulically operated booster, receiving its power from the power steering system, Fig. . The power steering pump provides fluid pressure to operate both the brake booster and the power steering gear. This fluid pressure provides a variable power assist that is regulated by brake pedal applic...

MASTER CYLINDER

The master cylinder consists primarily of a hydraulic cylinder, primary and secondary hydraulic pistons and a single or dual chamber fluid reservoir. The front brakes are connected to the primary outlet port(s) and are actuated by the primary piston assembly. The rear brakes are connected to the secondary outlet port and are actuated by the secondary piston assembly.

HYDRAULIC CONTROL VALVES

Combination Valve

This multi-function hydraulic control unit consists primarily of a pressure differential valve, brake lamp warning switch and a proportioning valve. A pressure diff...

Bleed primary and secondary hydraulic brake systems separately, bleeding the longest line first on each system. Do not allow reservoir to run dry during bleeding operation. Never reuse fluid that has been drained from the hydraulic system.

• Loosen master cylinder to hydraulic line nuts and wrap shop cloths around tubing below fitting to absorb escaping brake fluid.
• Depress brake pedal slowly forcing air trapped in master cylinder out at fitting.
• Hold pedal down and tighten fittings, then release brake pedal. Releasing brake pedal before fittings are tightened will allow air to ...

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 precautions should be taken to 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...

RAIL SLIDER CALIPER

Removal

• Drain a small amount of brake fluid from master cylinder reservoir.
• Raise and support vehicle, then remove wheel and tire assembly.
• Install an eight inch C-clamp on caliper housing and tighten clamp to bottom piston(s) in cylinder bore(s), then remove clamp. Do not use screwdriver or other edged tool to pry piston(s) from rotor.
• Remove key retaining screw, then using a hammer and drift, drive out caliper support key and spring.
• On single piston calipers, push caliper downward against spindle, then rotate upper end upward and out of spindle assembly.
• On dua...