1990 Mercury Grand Marquis Brake Service (ONLINE REPAIR MANUALS)

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...

Whenever new brake components are installed in the hydraulic system, it is recommended that the entire hydraulic system be thoroughly flushed with clean brake fluid.

It may sometime become necessary to flush out the system due to the presence of mineral oil, kerosene, gasoline, etc., which will cause swelling of rubber piston cups and valves so they become inoperative. The procedure is as follows:

Flushing is ...

DISASSEMBLY

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

• Remove caliper assembly from vehicle as described under "Caliper, Replace."
• Position fiber block and shop towels between caliper piston and caliper housing, then apply compressed air to caliper brake line fitting bore to force piston from caliper.
• Remove dust boot from caliper assembly,Figs. and .
• Remove piston seal from cylinder and discard.

Festiva

• Remove brake pads and caliper as outlined previously.
• Remove bleeder screw, drain remaining fluid from caliper, then reinstall screw.
• Remove dust boot retaining r...

Pressure bleeding is recommended for all hydraulic brake systems.

The bleeding operation itself is fairly well standardized. First step in all cases is cleaning the dirt from the filler cap before removing it from the master cylinder. This should be done thoroughly.

Pressure bleeding is fastest because the master cylinder doesn't have to be refilled several times, and the job can be done by one man. To prevent air from the pressure tank getting into the lines, do not shake the tank while air is being added to the tank or after it has been pressurized. Set the tank in the required ...

• Lightly lubricate backing plate shoe contact surfaces with suitable brake lube.
• On type 1 brakes, assemble parking brake lever to secondary shoe and secure with spring washer and retaining clip. Crimp ends of clip with suitable pliers.On type 2 brakes, engage parking brake lever tang with secondary shoe.
• Position brake shoes on backing plate, primary (short lining) shoe facing front of vehicle and secondary (long lining) facing rear. Secure brake shoes with hold-down springs, pins and retainers.
• Install parking brake link and spring between shoes.
• Loosen parking brake adjustment nut, t...

• Grease or any other foreign material must be kept off the caliper, surfaces of the disc and external surfaces of the hub, during service procedures. Handling the brake disc and caliper should be done in a way to avoid deformation of the disc and nicking or scratching brake linings.
• If inspection reveals rubber piston seals are worn or damaged, they should be replaced immediately.
• During removal and installation of a wheel assembly, exercise care so as not to interfere ...