See Figures 1, 2 and 3
The primary (front) and secondary (rear) hydraulic systems are independent of each other. If it is known that only one system has air in it, only that system has to be bled. Bleed the longest line first on the individual system being serviced.
- Fill the master cylinder with brake fluid.
- If the secondary system is to be bled, install a 3 / 8 in. box-end wrench on the bleeder screw of the right rear wheel cylinder. Be sure to first remove the screw's protective cap, if so equipped.
- Push a piece of small diameter rubber or plastic tubing over the bleeder screw until it is flush against the wrench. Submerge the other end of the tubing in a glass jar partially filled with clean brake fluid. Make sure the tubing fits on the bleeder screw snugly.
- Open the bleeder screw approximately 3 / 4 turn and have an assistant apply pressure to the brake pedal. Observe the bottle of brake fluid. If bubbles appear in the glass jar, there is air in the system. When your assistant has pushed the pedal to the floor, immediately close the bleeder screw before he releases the pedal.
- Repeat this operation until air bubbles cease to appear at the submerged end of the bleeder tubing.
- When the fluid is completely free of air bubbles, tighten the bleeder screw and remove the bleeder tubing. Replace the protective cap on the bleeder screw, if so equipped.
- Repeat this procedure at the left rear wheel cylinder. Refill the master cylinder reservoir after each wheel cylinder is bled. Do not allow the master cylinder to run dry.
- If the primary system is to be bled, repeat steps 3-6, beginning with the right front caliper. (On disc brake systems, which do not use wheel cylinders, bleeder screws are located on the brake calipers.)
- Repeat the bleeding procedure at the left front brake caliper.
- Check the fluid level in the master cylinder and center the pressure differential warning valve, as described earlier in this section.