See Figures 1, 2 and 3
It is necessary to bleed the hydraulic system any time system has been opened or any other time air has become trapped within the fluid lines. It may be necessary to bleed the system at all four brakes if air has been introduced through a low fluid level or by disconnecting brake pipes at the master cylinder.
Vehicles equipped with Anti-Lock Brake Systems (ALB/ABS) require separate bleeding procedures if any of the ALB/ABS components have been removed or the lines disconnected. Refer to the procedure later in this section.
If a line is disconnected at one wheel only, generally only that brake circuit needs bleeding, although bleeding all four wheels is always recommended. If lines are disconnected at any fitting between the master cylinder and the brake, the components fed by the disconnected pipe must be bled.
On vehicles with rear drum brakes, mis-adjusted brake shoes can cause a "long" pedal and reduced braking, giving the illusion of air in the lines. If you're trying to track down such a problem, adjust the rear brakes and test drive the car before bleeding the system.
- Start bleeding by filling the master cylinder reservoir to the MAX or FULL line with fresh brake fluid from a sealed container and keep it at least half full throughout the bleeding procedure.
It is strongly recommended that any time bleeding is to be performed all wheels be bled rather than just one or two. The correct order of bleeding is:
1984-87 Models: left front, right rear, right front, left rear.
- At the wheel to be bled, Place the correct size box-end or line wrench over the hex on the bleeder valve, then attach a tight-fitting hose over the bleeder opening. Allow the tube to hang submerged in a transparent container half full of clean brake fluid. The hose end must remain submerged in the fluid at all times.
- Have an assistant pump the brake pedal several times slowly and hold it down.
- Slowly unscrew the bleeder valve ( 1 / 4 - 1 / 2 turn is usually enough). After the initial rush of air and fluid, tighten the bleeder and have the assistant slowly release the pedal.
DON'T allow your assistant to release the pedal while the bleeder valve is still loose or air may be drawn back into the system.
- Repeat until no air bubbles are seen flowing from the bleeder to the hose or container. If air is constantly appearing after repeated bleeding, the system must be examined for the source of the leak or loose fitting. When finished with a wheel, the bleeder screw should be tightened to 5-7 ft. lbs. (7-9 Nm).
- Periodically check the reservoir on the master cylinder, topping it as needed to maintain the proper level. If the master cylinder level is allowed to drop significantly during this procedure, it is possible to draw air back into the system, thus defeating your bleeding efforts up to that point.
- After bleeding, check the pedal for "sponginess" or vague feel. Repeat the bleeding procedure as necessary to correct. Top off the reservoir level.
- Test drive the car to check proper brake function. But DO NOT attempt to move the car unless a firm brake pedal is felt.