'87-96 Master Cylinder
IF THE IMAGE IS TOO SMALL, click it.
'87-93 1/2-ton, & '87-96 w/o cruise
Motorcraft BRMC63 (F4TZ2140E)
'94-96 w/cruise F4TZ2140FA
2004 - Master Cylinder Piston Assembly & Retainer Screw
2140 - Master Cylinder
2162 - Reservoir Cap
2C161 -
Fluid Control Valve Assembly F8UZ-2C161-AA2L454 - Brake Fluid Reservoir
# - threaded nipple for SCCDS ('94-96 only)
Line ports are 1/2-20 and 7/16-24 inverted flare.
The brake pressure control valve (fluid control valve) regulates the hydraulic pressure in the rear brake system. It is located between the rear brake system's inlet and outlet ports in the main valve. When the brake pedal is applied, the full brake fluid pressure passes through the brake pressure control valve to the rear brake system until the valve's split point is reached. Above its split point, the brake pressure control valve begins to reduce the hydraulic pressure to the rear brakes, creating a balanced braking condition between the front and rear wheels to minimize rear wheel lock-up during hard braking. In case of the front brake system malfunction, the brake master cylinder fluid control valve has a bypass feature, which allows full hydraulic pressure to the rear brake system.
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Reverse-Bleeding Procedure (for air ONLY in the MC, HCU, & lines - not cylinders):
(Note that the entire system can be reverse-bled without opening any slave bleed valves, provided all their fluid ports are oriented to the top.)
1) Remove the cap from the reservoir.
2) Compress the RHR wheel cylinder fully by flipping one rubber boot forward and stabbing a flat screwdriver against the face of the piston beside the pushrod (catching any fluid that spills out of the reservoir); then allow it to slowly extend, making sure the pushrods remain properly-seated in the pistons & shoes. Repeat for the LHR.
3) Compress the RHF caliper piston fully, then the LHF, using a prybar between the outer pad & rotor.
4) Use a squeeze bulb to remove as much fluid as possible from the reservoir, and refill with fresh fluid from a sealed container.
5) Pump up the pedal (keeping fluid in the reservoir) & check for normal pedal feel with the engine idling. If air is still suspected in the system, use the following procedure...
Reverse-Bleeding Procedure for air in the wheel cylinders (as opposed to air only in the lines):
1) Remove the cap from the reservoir & fill it TO THE TOP with fresh fluid from a sealed container.
2) Then remove the pushrods from the RHR slave so the pistons can FULLY extend, drawing as much fluid as possible inside. If necessary, gently press the pedal to force the pistons out.
3) Open the bleeder & let out as much air as possible; then close the bleeder. Top up the reservoir & repeat for the LHR slave.
4) Replace the pushrods so the shoes & springs fully compress the slaves, driving air back to the reservoir. Prepare for fluid to spill out - keep it off the paint.
5) Pull the calipers off, remove the outboard pads, and put the calipers back in-place on the rotors.
6) Pump the pedal to fill them (the rotors SHOULD keep the pistons from shooting out, but check frequently and DON'T shoot the piston out of the caliper), top up the reservoir, and gravity-bleed them through the bleeders.
7) Use a squeeze bulb to remove as much fluid as possible from the reservoir, and fully compress the R caliper, then the L, then reassemble the pads properly.
8 ) Use a squeeze bulb to remove as much fluid as possible from the reservoir, and refill with fresh fluid from a sealed container.
9) Pump up the pedal (keeping fluid in the reservoir) & check for normal pedal feel with the engine idling.
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Hydraulic System Bleeding (Ford RABS procedures)
When any part of the hydraulic system has been disconnected for repair or replacement, air may get into the lines and cause spongy pedal action. This requires the bleeding of the hydraulic system after it has been properly connected to be sure all air is expelled from the brake cylinders and lines. The hydraulic system can be bled with pressure bleeding equipment such as Rotunda Brake Bleeder model 104-00064 or equivalent. Bleed one brake cylinder at a time. On E-150-250-350, F-150-250-350 and '87-92 Bronco vehicles, start the bleeding at the right rear brake wheel cylinder and then at the left rear wheel brake cylinder. After completing, proceed to the Rear Anti-lock Brake (RABS) Valve. Then proceed to bleed the front brakes, starting with the right front brake, and finish bleeding on the left front brake. On F-Super Duty vehicles, start the bleeding at the right rear brake, then the left rear brake. After completing, proceed to bleed the right front brake and then the left front brake. Keep the master cylinder reservoir filled with the specified Ford Heavy Duty Brake Fluid C6AZ-19542-AA or -BA (ESA-M6C25-A) or equivalent. Never use brake fluid that has been drained from the system.
When a brake master cylinder (2140) 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 (2264) 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 (2K478 ) with new Ford High-Performance DOT 3 Brake Fluid C6AZ-19542-AA or -BA or DOT 3 equivalent meeting Ford specification ESA-M6C25-A.
4. 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. 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 (2B253) 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 (2455) 10 times and then hold firm pressure on the brake pedal.
- b. Loosen the rearmost 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.
7. If any of the brake tubes, disc brake calipers (2B120), or rear wheel cylinders have been removed, it may be helpful to prime the system by gravity bleeding. This should be done after the brake master cylinder is primed and bled. To gravity bleed the brake system:
- a. Fill the brake master cylinder with new Heavy-Duty Brake Fluid C6AZ-19542-AA or -BA or DOT 3 equivalent meeting Ford specification ESA-M6C25-A.
- b. Loosen both of the wheel cylinder bleeder screws and leave them open until clear brake fluid flows. Be sure to check the brake master cylinder reservoir fluid level often and do not let it run dry.
- c. Tighten the wheel cylinder bleeder screws (2208 ) to 7-9 N-m (61-87 lb-in).
- d. One at a time, loosen the caliper bleeder screws. Leave the bleeder screws open until clear fluid flows. Check the fluid level often in the brake master cylinder reservoir and do not let it run dry.
- e. Tighten the caliper bleeder screws to 17-24 N-m (12-17 lb-ft).
8. After the brake system has been primed, bleed the brake system at each wheel (1007).
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See also:
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