1991 Mercury Topaz Brake Service (ONLINE REPAIR MANUALS)

• Remove wheel, drum and brake shoes.
• Disconnect hydraulic line at wheel cylinder. Do not pull metal line away from cylinder as the cylinder connection will bend metal line and make installation difficult. Line will separate from cylinder when cylinder is moved away from brake backing plate.
• Remove screws holding cylinder to brake plate and remove cylinder.

OVERHAUL

• Referring toFig. as a guide, remove boots, pistons, springs and cups from cylinder.
• Place all parts, except cylinder casting in clean brake fluid. Wipe cylinder walls with clean brake fluid.
• Examine cylinder bore. A scored ...

The caliper assembly consists of a pin slider caliper housing, inner and outer shoe and lining assemblies and a single piston,Figs. and . The caliper slides on two pins which also act as attaching bolts between caliper and the combination anchor plate and spindle. The outer brake shoe and lining assembly is longer than the inner brake shoe and lining assembly. Inner and outer shoe and lining assemblies are attached to the caliper by spring clips riveted to the shoe surfaces. The inner shoe is attached to the caliper by installing the spring clip to the inside of the caliper piston. T...

REMOVAL

Except Capri, Festiva, Tracer, Scorpio, XR4Ti, Probe & 1991 Escort

• Remove brake fluid until reservoir is half full.
• Raise and support front of vehicle, then remove wheel and tire assembly.
• Remove caliper locating pins.
• Lift caliper assembly from adapter plate, then remove outer shoe from caliper assembly.On some models, slip shoe down caliper leg until clip is disengaged.
• Remove inner shoe and lining assembly.On some models, pull shoe straight out of piston. This should require a force as high as 20-30 lbs.
• Suspend caliper from inner fender housing with wire to avoid damaging brake ...

DESCRIPTION

The proportioning valve (when used),Fig. , provides balanced braking action between front and rear brakes under a wide range of braking conditions. The valve regulates the hydraulic pressure applied to the rear wheel cylinders, thus limiting rear braking action when high pressures are required at the front brakes. In this manner, premature rear wheel skid is prevented.

TESTING

When a premature rear wheel slide is obtained on a brake application, it usually is an indication that the fluid pressure to the rear wheels is above the 50% reduction ratio for the rear line ...

DESCRIPTION

These units are of the vacuum suspended type. Some units are of the single diaphragm type,Fig. while others are of the tandem diaphragm type,Fig. . Both single piston and double piston or split system type master cylinders are used.

The vacuum suspended diaphragm type units utilize engine manifold vacuum and atmospheric pressure for its power. It consists of three basic elements combined into a single power unit. The three basic elements of the single diaphragm type are:

• A vacuum power section which includes a front and rear shell, a power diaphragm...

BRAKE DRUMS

Any time the brake drums are removed for brake service, the braking surface diameter should be checked with a suitable brake drum micrometer at several points to determine if they are within the safe oversize limit stamped on the brake drum outer surface. If the braking surface diameter exceeds specifications, the drum must be replaced. If the 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. Mi...