FILLING THE SYSTEM
- Turn the ignition OFF and leave it OFF during inspection.
- Thoroughly clean the reservoir cap and the surrounding area.
- Carefully remove reservoir cap, keeping all dirt out of the reservoir. Inspect the fluid level; fill to the top of the white screen in the front strainer if required. Do not overfill. Use only fresh DOT 3 brake fluid from unopened containers. Do not use any fluid containing a petroleum base. Do not use any fluid which has been exposed to water or moisture. Failure to use the correct fluid will affect system function and component life.
- Install the reservoir cap.
BLEEDING THE SYSTEM
Bleeding may be done either manually, or with vacuum/pressure equipment. Bleed only one brake component at a time. The recommended bleed sequence is:
The individual lines may be bled manually at each wheel using the traditional 2-person method.
Use DOT 3 brake fluid, or an equivalent meeting SAE J1703-F and DOT 3 standards.
Bleed a new or overhauled master cylinder on the bench before installation.
- Components should be bled in the proper order. Connect a transparent hose to the bleed screw. Submerge the other end of the hose in clean brake fluid in a clear glass container.
- Have a helper press and HOLD the brake pedal to the floor. Observe the condition of the escaping fluid.
- Tighten the fitting, then have the helper release the brake pedal.
- Repeat Steps 2 and 3 until air-free fluid flows from the hose. Tighten the caliper bleed screw to 60-84 inch lbs. (7-9 Nm).
- Repeat the sequence at each remaining caliper and wheel cylinder.
Check the fluid level in the reservoir frequently and maintain it near the full level.
- When the bleeding is complete, bring the fluid level in the reservoir to the correct level. Install the reservoir cap.
See Figures 1 and 2
If a new front anti-lock valve assembly was installed, bleed it as follows:
- Loosen the bleed plug on the new front valve about 1 / 4 to 1 full turn. The plug must be open to completely bleed the upper and lower portions of the valve.
- Remove the bleeder valve cap, then install a valve depressor tool, such as tool No. 6670, or equivalent, on the bleed valve stem by sliding the notched side of the tool onto the boss that surrounds the bleed valve stem.
- Tighten the thumbscrew on the special tool enough to push the stem in about 0.020-0.030 in. (0.51-0.76mm). The stem must be held inward (open position) to completely bleed the upper portion of the new valve assembly.
- Apply the brake pedal. The pedal will fall off significantly if the tool is correctly installed.
- Stroke the brake pedal rapidly about 5-10 times. This action will fill the upper and lower portions of the valve rapidly.
- Bleed the new valve assembly at each brake line fitting, one at a time. Remember to close the valve bleed plug before each brake pedal stroke.
- Repeat the bleeding sequence for each brake line fitting until air-free fluid flows from the hose. Tighten the caliper bleed screw to 60-84 inch lbs. (7-9 Nm).
If the original assembly is being used, the bleed plug and bleed valve do not have to be open during the bleeding operations. Just bleed the valve assembly at each brake line fitting one at a time.
Bleed the first wheel brake unit and follow through in the proper sequence. When the fluid is clear and free of bubbles, tighten the caliper bleed screw to 60-84 inch lbs. (7-9 Nm). Then top off the master cylinder and verify the brakes operate properly.Vacuum Bleeding
If vacuum bleeding equipment is being used, it is not necessary to hold the front metering valve open. Simply bleed the brakes following the bleed equipment manufacturer's instructions.Pressure Bleeding
If pressure bleeding equipment is being used, the front brake metering valve will have to be held open to bleed the front brake lines. The valve stem is located in the forward end of the combination valve. The stem must be either pressed inward, or held outward slightly. A spring clip tool or a helper is needed to hold the valve stem in position.
Follow the equipment manufacturer's instructions when bleeding the brake lines. Generally a tank pressure of 15-20 psi (103-138 kPa) is more than sufficient for bleeding purposes. Do not exceed the tank manufacturer's pressure recommendations.
Fill the bleeder tank with the recommended fluid and purge the air from the tank prior to bleeding the lines.WARNING
Do not pressure bleed without a proper master cylinder adapter. The wrong adapter can lead to leakage or drawing air back into the system.
Make sure the front brake metering valve in the combination valve is held open. A spring clip tool is best for securing the valve stem in an open position.