Base Brake System
STANDARD PROCEDURE - BASE BRAKE BLEEDINGNOTE: This bleeding procedure is only for the vehicle's base brakes hydraulic system.
CAUTION: Before removing the master cylinder cover, thoroughly clean the cover and master cylinder fluid reservoir to prevent dirt and other foreign matter from dropping into the master cylinder fluid reservoir.
NOTE: The following wheel sequence should be used when bleeding the brake hydraulic system. The use of this wheel sequence will ensure adequate removal of all trapped air from the brake hydraulic system.
^ Left Rear Wheel
^ Right Front Wheel
^ Right Rear Wheel
^ Left Front Wheel
NOTE: When bleeding the brake system, some air may be trapped in the brake lines or valves far upstream, as much as ten feet from the bleeder screw. Therefore, it is essential to have a fast flow of a large volume of brake fluid when bleeding the brakes to ensure all the air gets out.
The brakes may be manually bled or pressure bled. Refer to the appropriate following procedure.
MANUAL BLEEDING PROCEDURE
NOTE: Correct manual bleeding of the brakes hydraulic system will require the aid of a helper. To adequately bleed the brakes using the manual bleeding procedure the rear brakes must be correctly adjusted. Prior to the manual bleeding of the brake hydraulic system, correctly adjust the rear brakes.
1. Pump the brake pedal three or four times and hold it down before the bleeder screw is opened.
2. Push the brake pedal toward the floor and hold it down. Then open the left rear bleeder screw at least 1 full turn. When the bleeder screw opens the brake pedal will drop all the way to the floor.
CAUTION: "Just cracking" the bleeder screw often restricts fluid flow, allowing only a slow, weak fluid discharge of fluid. This practice will NOT get all the air out. Make sure the bleeder is opened at least 1 full turn when bleeding.
3. Release the brake pedal only after the bleeder screw is closed.
4. Repeat steps 1 through 3, four or five times, at each bleeder screw in the proper sequence. This should pass a sufficient amount of fluid to expel all the trapped air from the brake system. Be sure to monitor the fluid level in the master cylinder, so it stays at a proper level so air will not enter the brake system through the master cylinder.
5. Check pedal travel. If pedal travel is excessive or has not been improved, enough fluid has not passed through the system to expel all the trapped air. Continue to bleed system as necessary.
6. Perform a final adjustment of the rear brake shoes (when applicable), then test drive vehicle to be sure brakes are operating correctly and that pedal is solid.
PRESSURE BLEEDING PROCEDURE
CAUTION: Use bleeder tank Special Tool C-3496-B or equivalent with Adapter, Special Tool 6921, to pressurize the hydraulic system for bleeding.
Follow pressure bleeder manufacturer's instructions for use of pressure bleeding equipment.
1. Install the Adapter Master Cylinder Pressure Bleed Cap, Special Tool 6921 on the fluid reservoir of the master cylinder. Attach the fluid hose from the pressure bleeder to the fitting on Special Tool 6921.
2. Attach a clear plastic hose to the bleeder screw at one wheel and feed the hose into a clear jar containing fresh brake fluid.
3. Open the left rear wheel bleeder screw at least one full turn or more to obtain an adequate flow of brake fluid.
CAUTION: "Just cracking" the bleeder screw often restricts fluid flow, allowing only a slow, weak fluid discharge of fluid. This practice will NOT get all the air out. Make sure the bleeder is opened at least 1 full turn when bleeding.
4. After 4 to 8 ounces of brake fluid has been bled through the hydraulic system, and an air-free flow is maintained in the hose and jar, this will indicate a good bleed of the hydraulic system has been obtained.
5. Repeat the procedure at all the other remaining bleeder screws.
6. Check pedal travel. If pedal travel is excessive or has not been improved, enough fluid has not passed through the system to expel all the trapped air. Be sure to monitor the fluid level in the pressure bleeder, so it stays at a proper level so air will not enter the brake system through the master cylinder.
7. Perform a final adjustment of the rear brake shoes (when applicable), then test drive vehicle to be sure brakes are operating correctly and that pedal is solid.