See Figures 1 and 2
The 4-Wheel Anti-Lock system can be bled in much the same way as a conventional brake system. Bleeding manually or with vacuum/pressure equipment can be performed as long as the recommended bleeding sequence is followed. Bleed only one brake component at a time. The recommended bleeding sequence is: master cylinder, combination valve, rear anti-lock valve, front anti-lock valve, left rear wheel, right rear wheel, right front wheel, left front wheel.
If a new front anti-lock valve assembly is installed, bleed the new valve as follows:
- Loosen the bleed plug on the new front valve about 1 / 4 to one full turn. The plug must be open to fully bleed the upper and lower sections of the front hydraulic valve.
- Remove the cap from the bleed valve stem.
- Install a valve depressor tool, or equivalent. A helper can also be used to hold the valve in the proper position. Insert the tool on the valve stem by sliding the notched side of tool onto the boss that surrounds the bleed valve stem.
- Tighten the thumbscrew on the tool just enough to push the valve stem inward about 0.020-0.030 in. (0.51-0.76mm). The stem must be held inward in an open position to fully bleed the upper section of the new valve assembly.
- Apply the brake pedal. The pedal will fall off significantly when the bleed plug is properly open and the bleed valve stem is correctly unseated (pressed inward).
- Rapidly depress the brake pedal 5-10 times. This action will fill the upper and lower sections of the valve rapidly.
- Bleed the new valve assembly at each brake line. Only bleed one fitting at a time. Remember to close the valve bleeding plug before each brake pedal stroke. Continue bleeding until fluid flowing from the fittings is clear and free of bubbles.
- Remove the depressor tool from the valve stem and install the cap on the stem. Then, tighten the bleed plug to 60-84 inch lbs. (7-9 Nm).
If the original front anti-lock assembly is being used, the bleed plug and bleed valve do not have to be open during bleeding operations.