1991 Ford Festiva Brake Service (ONLINE REPAIR MANUALS)

Complaints about power brake operation should be handled as if two separate systems exist. Check for faults in the hydraulic system first. If it is satisfactory, start inspecting the power brake circuit. For a quick check of proper power unit operation, press the brake pedal firmly and then start the engine. The pedal should fall away slightly and less pressure should be needed to maintain the pedal in any position.

Another check begins with installation of a suitable pressure gauge in the brake hydraulic system. Take a reading with the engine off and the power unit not opera...

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 ...

• 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 ...

• Clean backing plate with a factory approved vacuum cleaner.
• Lubricate backing plate shoe pads with suitable high temperature brake grease.
• Install and position parking brake strut/self adjuster onto backing plate.
• Install upper return spring to primary brake shoe, then position shoe on backing plate and install retaining pin and hold down clip,Fig. .
• Connect upper return spring to secondary brake shoe, then position secondary shoe on backing plate...

BENDIX, TEVES & DOUBLE DIAPHRAGM BOOSTER

On Bendix, Teves and Double Diaphragm Booster type power brake units, overhaul is not required. If it has been determined that the brake booster is defective, replace power brake unit as an assembly. In some instances, the only service required is replacement of the check valve and grommet and pushrod adjustment.

SINGLE DIAPHRAGM BOOSTER

Disassembly

• Remove brake booster from vehicle.
• Place front shell of booster in a vise.
• Remove clevis from valve rod and plunger assembly.
• Remove dust boot from rear shell,Fig. , then place alignment marks on fron...

Never use copper tubing as a replacement for steel tubing. Copper tubing is subject to fatigue cracking and corrosion which could result in brake system

Steel tubing is used to conduct hydraulic pressure to the brakes. All fittings, tubing and hose should be inspected for rusted, damaged or defective flared seats. The tubing is equipped with a double flare/inverted seat or I.S.O. flare to insure more positive seating in the fitting. To repair or reflare tubing, proceed as follows:

DOUBLE FLARE/INVERTED SEAT

• Using the tool shown inFig. or equivalent, cut off the damaged seat or da...