F 250 4WD HD Pickup V8-460 7.5L VIN G EFI (1997)
Brake Master Cylinder: Service and Repair
Master Cylinder, Brakes
Bench
WARNING: BRAKE FLUID CONTAINS POLYGLYCOL ETHERS AND POLYGLYCOLS. AVOID CONTACT WITH EYES. WASH
HANDS THOROUGHLY AFTER HANDLING. IF BRAKE FLUID CONTACTS EYES, FLUSH EYES WITH RUNNING
WATER FOR 15 MINUTES. GET MEDICAL ATTENTION IF IRRITATION PERSISTS. IF TAKEN INTERNALLY, DRINK
WATER AND INDUCE VOMITING. GET MEDICAL ATTENTION IMMEDIATELY.
1. Support the brake master cylinder body in a vise, and fill both fluid brake master cylinder reservoirs with Ford High Performance DOT 3 Brake
Fluid G6AZ-19542-AA or equivalent DOT 3 fluid meeting Ford specification ESA-M6C25-A.
2. Install plugs in the front and rear brake outlet ports. Bleed the front brake system first.
3. Loosen the plug in the front brake outlet port. Depress the primary piston slowly to force the air out of the brake master cylinder.
4. Tighten plug while piston is depressed or air will enter the brake master cylinder.
5. Repeat this procedure until air ceases to exit at the outlet port.
6. Repeat Steps 3, 4 and 5, for the rear brake outlet port with the front brake outlet plugged.
7. Tighten the plugs and try to depress the piston. The piston will not depress if all air bubbles are out of the brake system.
8. Install the brake master cylinder filler cap.
9. Install the brake master cylinder in the vehicle and bleed the brake system.
In-Vehicle
When a brake master cylinder has been installed, or the brake system emptied or partially emptied, fluid may not flow from the wheel cylinder bleeder
screws during normal bleeding. It may be necessary to prime the brake master cylinder using the following procedure.
1. Use a tubing wrench to remove the front brake tube and the brake master cylinder outlet rear tube from the brake master cylinder.
2. Install short brake tubes in the brake master cylinder and position them so that they curve into the brake master cylinder reservoir, and the ends of
the tubes are submerged in brake fluid.
3. Fill the brake master cylinder reservoir with new Ford High Performance DOT 3 Brake Fluid C6AZ-19542-AA or equivalent DOT 3 fluid meeting
Ford specification ESA-M6C25-A.
CAUTION: Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled onto a painted or plastic surface, immediately wash it
with water.
4. Have an assistant pump the brakes until clear, bubble-free fluid flows from both brake tubes.
5. Remove the short brake tubes and reinstall the front brake tube and brake master cylinder outlet rear tube on the brake master cylinder.
6. Bleed each brake tube at the brake master cylinder using the following procedure:
a. Have an assistant pump the brake pedal 10 times and then hold firm pressure on the brake pedal.
b. Loosen the rear most brake tube fittings with a tubing wrench until a stream of brake fluid comes out. Have an assistant maintain pressure on
the brake pedal until the brake tube fitting is tightened again.
c. Repeat this operation until clear, bubble-free fluid comes out from around the tube fitting. Refill the brake master cylinder reservoir as
necessary.
d. Repeat this bleeding operation at the front brake tube fittings.
Disassembly and Assembly
WARNING: BRAKE FLUID CONTAINS POLYGLYCOL ETHERS AND POLYGLYCOLS. AVOID CONTACT WITH EYES. WASH
HANDS THOROUGHLY AFTER HANDLING. IF BRAKE FLUID CONTACTS EYES, FLUSH EYES WITH RUNNING
WATER FOR 15 MINUTES. GET MEDICAL ATTENTION IF IRRITATION PERSISTS. IF TAKEN INTERNALLY, DRINK
WATER AND INDUCE VOMITING. GET MEDICAL ATTENTION IMMEDIATELY.
DISASSEMBLY