See Figures 1, 2 and 3
REMOVAL & INSTALLATION
Brake fluid acts like paint remover. Be certain not to spill brake fluid on the vehicle's painted surfaces.
- Disconnect the negative battery cable.
- Disconnect any brake sensor harnesses which may be attached to the master cylinder.
- Disconnect and plug the brake lines from the primary and secondary outlet ports of the master cylinder and pressure control valves.
- Remove the nuts attaching the master cylinder to the brake booster assembly.
- Slide the master cylinder forward and upward from the vehicle.
Before installation, bench bleed the new master cylinder as follows:
- Mount the new master cylinder in a suitable holding fixture. Be careful not to damage the housing.
- Fill the master cylinder reservoir with clean brake fluid.
- Using a suitable tool inserted into the booster pushrod cavity, carefully push the master cylinder piston in slowly. Place a container under the master cylinder to catch the fluid being expelled from the outlet ports.
- Place a finger tightly over each outlet port and allow the master cylinder piston to return.
- Repeat the procedure until clear fluid only is expelled from the master cylinder. Plug the outlet ports and remove the master cylinder from the holding fixture.
- Position the master cylinder over the booster pushrod and booster mounting studs. Install the nuts and tighten to 13-25 ft. lbs. (18-33 Nm).
- Remove the plugs individually and connect the brake lines. Tighten the fittings.
- Make sure the master cylinder reservoir is full. Have an assistant push down on the brake pedal. When the pedal is all the way down, crack open the brake line fittings, 1 at a time, to expel any remaining air in the master cylinder and brake lines. Tighten the fittings, then have the assistant allow the brake pedal to return.
- Repeat Step 9 until all air is expelled from the master cylinder and brake lines. Final tighten the brake line fittings to 10-18 ft. lbs. (14-24 Nm).
- Connect the brake warning indicator connector.
- Make sure the master cylinder reservoir is full.
- If necessary, bleed the brake system.
- Connect the negative battery cable. Check for fluid leaks and check for proper operation.
- Road test the vehicle.
See Figures 4, 5, 6, 7 and 8
- Remove master cylinder from vehicle. Clean any dirt from the body of the assembly. Place master cylinder in suitable vise. Take care not to damage the brake housing.
- Drain any brake fluid from master cylinder and dispose of properly.
Never reuse brake fluid
- Remove master cylinder reservoir from metal body.
- Depress the primary piston and remove the snapring from the retaining groove at the end of the bore.
- Remove the primary and secondary piston assemblies from the master cylinder. Tap open end of cylinder on the bench to remove the piston. If secondary piston does not readily come out, apply compressed air pressure to the secondary outlet port to assist removal.
- Remove fluid control valve.
- Wash the master cylinder body, especially the bore in clean brake fluid. Do the same to the primary and secondary pistons. Inspect the seals for cuts, nicks, scratches or other signs of wear, blistering or swelling. Replace parts as required. Inspect the master cylinder body and bore for pitting, corrosion or heavy wear characterized by scoring or galling of the metal.
- Dip the piston assembly in clean brake fluid, DOT 3 or equivalent. Install the secondary (smaller) piston assembly into the bore, spring end first.
- Install primary piston assembly, spring end first.
- Depress primary piston and install snapring.
- Install the fluid control valve.
- Position and secure fluid reservoir.
- Install master cylinder to booster. Bleed brake system.