Hydraulic Control Unit
Details regarding Brake Lines replacing:--
Details regarding Bleeding the Brake:---
- There are 5 ports on the EHCU( engine hydraulic control unit) the primary and secondary from the master cylinder, the primary connects in to the far right port, the secondary connects into the far left port.
- Disconnect the inlet hydraulic brake lines.
- Disconnect the outlet hydraulic brake lines.
2nd from left = Left Front Output
Center = Right Front Output
Center Right = Rear Output
Right = Rear Input
Hydraulic Control Unit
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- On Super Duty models, remove the air cleaner assembly.
- On Super Duty models, remove the EVAP canister.
- Detach the anti-lock brake control module electrical connectors.
- Disconnect and plug the hydraulic brake lines.
- Remove the HCU retaining bolts and remove the HCU.
- If necessary, remove the HCU bracket.
To install:
- If removed, install the HCU bracket.
- Position the HCU.
- Install and tighten the retaining bolts.
- Connect the hydraulic brake lines.
- Connect the anti-lock brake control module electrical connectors.
- On Super Duty models, install the EVAP canister.
- On Super Duty models, install the air cleaner assembly.
- Connect the negative battery cable.
- Bleed the 4-wheel ABS.
Master Cylinder
- Disconnect the negative battery cable.
- Detach the fluid level electrical harness connector from the master cylinder reservoir.
- If equipped with speed control, detach the brake pressure switch electrical harness connector.
- Disconnect and plug 2 brake lines at the brake master cylinder ports.
- If the vehicle is equipped with rear anti-lock brakes, remove 2 retaining nuts and position the RABS valve out of the way using care not to damage the brake lines.
- Remove the 2 brake master cylinder retaining nuts and remove the master cylinder.
To install:
- Bench bleed the brake master cylinder before installation.
- Place the brake master cylinder to the power brake booster. Install 2 retaining nuts and tighten to 21 ft. lbs. (29 Nm).
- If equipped, install the RABS valve and 2 retaining nuts. Tighten to 15-21 ft. lbs. (21-29 Nm).
- Unplug and connect 2 brake lines to the brake master cylinder ports and tighten the fittings to 11-15 ft. lbs. (15-20 Nm).
- If equipped, connect the brake pressure switch electrical harness connector.
- Connect the electrical harness connector to the low fluid level warning switch.
- Fill the brake master cylinder with clean DOT 3 or equivalent brake fluid from a closed container.
- Bleed the entire brake system following the proper procedure.
- Road test the vehicle and check for proper brake system operation.
Brake Hoses and Lines
Metal lines and rubber brake hoses should be checked frequently for leaks and external damage. Metal lines are particularly prone to crushing and kinking under the vehicle. Any such deformation can restrict the proper flow of fluid and therefore impair braking at the wheels. Rubber hoses should be checked for cracking or scraping; such damage can create a weak spot in the hose and it could fail under pressure.
Any time the lines are removed or disconnected, extreme cleanliness must be observed. Clean all joints and connections before disassembly (use a stiff bristle brush and clean brake fluid); be sure to plug the lines and ports as soon as they are opened. New lines and hoses should be flushed clean with brake fluid before installation to remove any contamination.
REMOVAL & INSTALLATION- Disconnect the negative battery cable.
- Raise and safely support the vehicle on jackstands.
- Remove any wheel and tire assemblies necessary for access to the particular line you are removing.
- Thoroughly clean the surrounding area at the joints to be disconnected.
- Place a suitable catch pan under the joint to be disconnected.
- Using two wrenches (one to hold the joint and one to turn the fitting), disconnect the hose or line to be replaced.
- Disconnect the other end of the line or hose, moving the drain pan if necessary. Always use a back-up wrench to avoid damaging the fitting.
- Disconnect any retaining clips or brackets holding the line and remove the line from the vehicle.
If the brake system is to remain open for more time than it takes to swap lines, tape or plug each remaining clip and port to keep contaminants out and fluid in.
To install:
- Install the new line or hose, starting with the end farthest from the master cylinder. Connect the other end, then confirm that both fittings are correctly threaded and turn smoothly using finger pressure. Make sure the new line will not rub against any other part. Brake lines must be at least 1/2 in. (13mm) from the steering column and other moving parts. Any protective shielding or insulators must be reinstalled in the original location.
- Using two wrenches as before, tighten each fitting.
- Install any retaining clips or brackets on the lines.
- If removed, install the wheel and tire assemblies, then carefully lower the vehicle to the ground.
- Refill the brake master cylinder reservoir with clean, fresh brake fluid, meeting DOT 3 specifications. Properly bleed the brake system.
- Connect the negative battery cable.
REMOVAL & INSTALLATION
1997-98 F-250HD, F-350 and F-SuperDuty
- With the engine OFF , depress the brake pedal several times to expel any vacuum.
- Disconnect the fluid level warning switch wire.
- Disconnect the hydraulic system brake lines at the master cylinder.
- Remove the master cylinder retaining nuts and remove the master cylinder.
To install:
- Position the master cylinder assembly on the booster and install the retaining nuts. Tighten the nuts to 18-25 ft. lbs. (25-34 Nm).
- Connect the hydraulic brake system lines to the master cylinder.
- Connect the wiring.
- Bleed the master cylinder.