Quest 1995-1996

Brake System Bleeding


Clean, high quality brake fluid is essential to the safe and proper operation of the brake system. You should always buy the highest quality brake fluid that is available. If the brake fluid becomes contaminated, drain and flush the system, then refill the master cylinder with new fluid. Never reuse any brake fluid. Any brake fluid that is removed from the system should be discarded. Also, do not allow any brake fluid to come in contact with a painted surface; it will damage the paint.

Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with the eyes and wash your hands thoroughly after handling brake fluid. If you do get brake fluid in your eyes, flush your eyes with clean, running water for 15 minutes. If eye irritation persists, or if you have taken brake fluid internally, IMMEDIATELY seek medical assistance.

When any part of the hydraulic system has been disconnected for repair or replacement, air may get into the lines and cause spongy pedal action (because air can be compressed and brake fluid cannot). To correct this condition, it is necessary to bleed the hydraulic system so to be sure all air is purged.

When bleeding the brake system, bleed one brake cylinder at a time, in the order given.

For vehicles without anti-lock brakes (ABS):

Right rear
Left front
Left rear
Right front

For vehicles with anti-lock brakes (ABS):

Left front
Right front
Left rear
Right rear

ALWAYS keep the master cylinder reservoir filled with brake fluid during the bleeding operation. Do not allow the reservoir to run dry. Never use brake fluid that has been drained from the hydraulic system, no matter how clean it is.

  1. Clean all dirt from around the master cylinder reservoir cap, remove the cap and fill the master cylinder reservoir to the MAX mark with new brake fluid .
  3. Clean the bleeder screws at all four wheels. The bleeder screws are located on the back of the brake backing plate (drum brakes) and on the top of the brake calipers (disc brakes).
  5. Attach a length of rubber hose over the bleeder screw and place the other end of the hose in a glass jar, submerged in brake fluid.
  7. Open the bleeder screw 1 / 2 - 3 / 4 turn. Have an assistant slowly depress the brake pedal.
  9. Close the bleeder screw and tell your assistant to allow the brake pedal to return slowly. Continue this process to purge all air from the system.
  11. When bubbles cease to appear at the end of the bleeder hose, close the bleeder screw and remove the hose. Tighten the bleeder screw to the proper torque:

    Front disc brake caliper bleeder screws: 12 - 17 ft. lbs. (17 - 24 Nm)
    Rear drum brake wheel cylinder bleeder screws: 61 - 87 inch lbs. (7 - 9 Nm)

  13. Check the master cylinder fluid level and add fluid accordingly. Do this after bleeding each wheel.
  15. Repeat the bleeding operation at the remaining three wheels.
  17. Refill the master cylinder reservoir, as necessary, using only new DOT 3 or equivalent brake fluid.

    Click image to see an enlarged view

    Fig. There are tools, such as this Mighty-Vac, available to assist in proper brake system bleeding. Follow the manufacturer-s instructions for proper use

    Click image to see an enlarged view

    Fig. Using the Mighty-Vac to bleed the rear brakes