Removal & Installation
- Disconnect the negative battery cable.
- For vehicles equipped with ABS, apply the brake pedal a few times to exhaust all the vacuum in the system.
- Disengage the brake warning indicator electrical connector.
- Disconnect the brake lines from the primary and secondary outlet ports of the master cylinder and the brake pressure control valve.
- For vehicles equipped with ABS, disconnect the Hydraulic Control Unit (HCU) supply hose at the master cylinder, then secure in a position to prevent the loss of brake fluid.
- Remove the nuts attaching the master cylinder to the brake booster assembly.
- Slide the master cylinder forward and upward from the vehicle.
In order to ease installation, bench bleed the master cylinder before installation:
- Mount the master cylinder in a holding fixture, such as a soft jawed vise. Be careful not to damage the master cylinder housing.
- Fill the master cylinder with brake fluid.
- Place a suitable container under the master cylinder to catch the fluid being expelled from the outlet ports. Using a suitable tool inserted into the booster pushrod cavity, push the master cylinder piston in slowly.
- Place a finger tightly over each outlet port, then allow the master cylinder piston to return.
- Repeat the procedure until only clear fluid is expelled from the master cylinder. Plug the outlet ports, then remove the master cylinder from the holding fixture.
- For vehicles equipped with ABS, install a new seal in the groove in the master cylinder mounting face.
- Mount the master cylinder over the booster pushrod and onto the two studs on the power brake booster assembly.
- Install the retaining nuts, then tighten them to 16-21 ft. lbs. (21-29 Nm).
- Attach the brake fluid lines to the master cylinder and the brake pressure control valve ports.
- For vehicles equipped with ABS, install the HCU supply hose to the master cylinder fitting, then secure it with the hose clamp.
- Connect the brake warning light wire.
- Fill the brake master cylinder with DOT 3 brake fluid to 0.16 in. (4.0mm) below the MAX lines on the side of the reservoir.
- Connect the negative battery cable, then bleed the brake system. For details, please refer to the procedure located later in this section.
- Operate the brakes several times, then check for external hydraulic leaks.