1990 Ford Ranger Brake Service (ONLINE REPAIR MANUALS)

• Remove caliper and linings.
• Drain brake fluid from caliper housing, then position housing in a vise.
• Pad area between piston(s) and caliper bridge, then apply compressed air to caliper fluid port to remove piston(s). If piston is seized and cannot be forced from caliper, tap lightly around cylinder bore area while applying air pressure. Use caution when applying air pressure, as piston(s) may develop considerable force from pressure build-up.
• Remove and discard molded rubber boot(s) and square cut seal(s) from caliper assembly.
• Thoroughly clean piston(s) and caliper assembly using ...

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 ...

BRAKE DRUMS

Any time brake drums are removed for brake service, braking surface diameter should be checked with a suitable micrometer at several points to determine if they are within the safe oversize limit stamped on the brake drum outer surface. If braking surface diameter exceeds specifications, the drum must be replaced. If braking surface diameter is within specifications, drums should be cleaned and inspected for cracks, scores, deep grooves, taper, out of round and heat spotting. If drums are cracked or heat spotted, they must be replaced. Minor scores should be remove...

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...

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...

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...