Aspen 2007, Durango 2005-2007

Manual Bleeding

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Manual bleeding requires two people and a degree of patience and cooperation.

  1. Follow the preparatory steps, above.
  2.  
  3. 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.
  4.  
  5. Have your assistant press down on the brake pedal, then open the bleeder screw 1 / 2 - 3 / 4 turn.
  6.  
  7. The brake pedal will go to the floor.
  8.  
  9. Close the bleeder screw-preferably before the pedal reaches the floor. Tell your assistant to allow the brake pedal to return slowly.
  10.  
  11. Repeat these steps to purge all air from the system.
  12.  
  13. When bubbles cease to appear at the end of the bleeder hose, close the bleeder screw and remove the hose. Check that the pedal is firm or at least more firm than it was when you started. If not, continue the procedure.
  14.  
  15. Check the master cylinder fluid level and add fluid accordingly. Do this after bleeding each wheel.
  16.  
  17. Repeat the bleeding operation at the remaining three wheels, ending with the one closet to the master cylinder.
  18.  
  19. Fill the master cylinder reservoir to the proper level.
    NOTE
    If there is excessive air in the system, it is possible that the stroke of the brake pedal will be insufficient to purge the lines. In this case a pressure bleeder or vacuum bleeder is the easiest solution.



    Click image to see an enlarged view

    Fig. Proper setup for manual bleeding procedure



    Click image to see an enlarged view

    Fig. Bleed screw caps are a must to keep the bleed screw passages clear



    Click image to see an enlarged view

    Fig. Lack of cap may cause bleeder screw passages to become clogged

  20.  


CAUTION
Bleeding of four-wheel Anti-lock brake systems require the use of a dedicated scan tool. Lines should not be disconnected unless one is available. The recommended procedure is to carry out a standard bleeding procedure, purge the HCU with the scan tool, then carry out another standard bleeding procedure.


NOTE
Add only fresh, clean brake fluid from a sealed container when bleeding the brakes.


NOTE
If pressure bleeding equipment is used, the front brake metering valve will have to be held open to bleed the front brakes. The valve stem is located in the forward end or top of the combination valve. The stem must either be pressed inward or held outward slightly. Follow equipment manufacturer's instructions carefully when using pressure equipment. Do not exceed the maker's pressure recommendations. Generally, a tank pressure of 15-20 psi is sufficient. Do not pressure bleed without the proper master cylinder adapter.

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.

Bleeding must start where the lines were disconnected. If lines were disconnected at the master cylinder, for example, bleeding must be done at that point before proceeding downstream.

When bleeding the brake system, bleed one brake cylinder at a time, beginning at the cylinder with the longest hydraulic line (farthest from the master cylinder) first. Failure to do so may result in more air being drawn into the lines.

If the existing system fluid seems dirty or if the vehicle has covered considerable mileage, it is recommended that the system be completely purged and refilled with fresh, clean fluid. The best way to start is to siphon the old fluid out of the master cylinder reservoir and fill it completely with fresh fluid.

Brake fluid tends to darken over time. This does not necessarily indicate contamination. Examine fluid closely for foreign matter.

The primary and secondary hydraulic brake systems are separate and are bled independently. During the bleeding operation, do not allow the reservoir to run dry. Keep the master cylinder reservoir filled with brake fluid. Never use brake fluid that has been drained from the hydraulic system, no matter how clean it seems.

  1. Clean all dirt from around the master cylinder fill cap, remove the cap and fill the master cylinder with brake fluid until the level is within 1 / 4 in. (6mm) of the top edge of the reservoir.
  2.  
  3. Clean the bleeder screws at all 4 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).
  4.  
  5. Bleeder screws should be protected with rubber caps. If they are missing, the orifice may easily become clogged with road dirt. If the screw refuses to bleed when loosened, remove it and blow clear. Aftermarket caps are readily available.
  6.  

Manual bleeding requires two people and a degree of patience and cooperation. Bleeding should be performed in this order: (1) Right rear, (2) Left rear, (3) Right front, (4) Left front.

  1. Follow the preparatory steps, above.
  2.  
  3. 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.
  4.  
  5. Have your assistant press down on the brake pedal, then open the bleeder screw 1 / 2 - 3 / 4 turn.
  6.  
  7. The brake pedal will go to the floor.
  8.  
  9. Close the bleeder screw-preferably before the pedal reaches the floor. Tell your assistant to allow the brake pedal to return slowly.
  10.  
  11. Repeat these steps to purge all air from the system.
  12.  
  13. When bubbles cease to appear at the end of the bleeder hose, close the bleeder screw and remove the hose. Check that the pedal is firm or at least more firm than it was when you started. If not, continue the procedure.
  14.  
  15. Check the master cylinder fluid level and add fluid accordingly. Do this after bleeding each wheel.
  16.  
  17. Repeat the bleeding operation at the remaining three wheels, ending with the one closet to the master cylinder.
  18.  
  19. Fill the master cylinder reservoir to the proper level.
    NOTE
    If there is excessive air in the system, it is possible that the stroke of the brake pedal will be insufficient to purge the lines. In this case a pressure bleeder or vacuum bleeder is the easiest solution.



    Click image to see an enlarged view

    Fig. Proper setup for manual bleeding procedure



    Click image to see an enlarged view

    Fig. Bleed screw caps are a must to keep the bleed screw passages clear



    Click image to see an enlarged view

    Fig. Lack of cap may cause bleeder screw passages to become clogged

  20.  

 
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