Toyota 4Runner 2001-06

Bleeding the Brake System

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Fig. If excessive pedal travel is detected, air may be trapped in the lines

It is necessary to bleed the hydraulic system any time the system has been opened or has trapped air 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.

If a line is disconnected at one wheel only, generally only that brake needs bleeding. If lines are disconnected at any fitting between the master cylinder and the brake, the system served by the disconnected pipe must be bled.


WARNING
Do NOT allow brake fluid to splash or spill onto painted surfaces; the paint will be damaged. If spillage occurs, flush the area immediately with clean water.



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Fig. Always keep the fluid in the brake fluid reservoir at the proper level when bleeding the system



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Fig. Location of the rear bleeder screw



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Fig. Remove the bleeder screw dust cap



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Fig. Loosen the bleeder screw with a line wrench



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Fig. Using a vinyl tube submerged in a container of brake fluid to bleed the brake system

  1. Fill the master cylinder to the maximum level with the proper brake fluid.
  2.  
  3. Attach a pressure bleeder to the master cylinder reservoir. Do NOT allow the pressure to exceed 29 psi (2 bar).
    NOTE
    An assistant will be needed to properly bleed the brake system.

  4.  
  5. Raise and safely support the vehicle.
  6.  
  7. Remove the protective caps from the bleeder screws and bleed the brakes using the following bleeding sequence. Always starts with the brake unit farthest from the master cylinder. The proper bleeding sequence is:

    Right rear
     
    Left rear
     
    Right front
     
    Left front.
     

  8.  
  9. Insert a tight fitting clear plastic tube over the bleeder screw on the caliper and the other end of the tube in a transparent container partially filled with clean brake fluid.
    WARNING
    When bleeding, do NOT allow the system to run dry, otherwise the entire procedure must be repeated.

  10.  
  11. Have an assistant slowly pump the brake pedal several times. On the last pump, have the assistant hold the pedal fully depressed. While the pedal is depressed, open the bleeder plug until fluid starts to run out, then close the plug.
    NOTE
    If the brake pedal is pumped too fast, small air bubbles will form in the brake fluid which will be very difficult to remove.

  12.  
  13. Repeat this procedure until no air bubbles are visible in the hose. Close the bleeder port.
    NOTE
    Constantly replenish the brake fluid in the master cylinder reservoir, so that it does not run out during bleeding.

  14.  
  15. If bleeding the entire system, repeat the procedure at the left rear wheel, the right front wheel and the left front wheel in that order.
  16.  

If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the system.

When bleeding, keep the amount of the fluid within the line of reservoir between Min. and Max.


WARNING
Do NOT allow brake fluid to splash or spill onto painted surfaces; the paint will be damaged. If spillage occurs, flush the area immediately with clean water.

 
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