GM Lumina/Silhouette/Transport APVs 1990-1999 Repair Guide

Bleeding the ABS System

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If any brake component is repaired or replaced such that air is allowed to enter the brake system, the entire bleeding procedure MUST be followed. On vehicles equipped with ABS, before bleeding the brakes, the front and rear displacement cylinder pistons must be returned to the topmost position. The preferred method uses a Tech 1®, or equivalent, scan tool to perform the re-homing procedure, If a Tech 1® is not available, the second procedure may be used, but it is extremely important that the procedure be followed exactly as outlined.

Fluid may be added to either reservoir in normal fashion. The ignition must be OFF . Carefully wipe the reservoir cap and surrounding area free of dirt and debris before removing the cap. Use only DOT 3 brake fluid from an unopened container. The use of DOT 5 or silicone brake fluid is specifically prohibited in this system. Fill the reservoir only to the MAX mark; do not overfill. Make certain the reservoir cap is securely installed.

RE-HOME PROCEDURE WITH TECH 1®



  1. Using a Tech 1® or equivalent scan tool, select "F5: Motor Re-home." The motor re-home function cannot be performed if current DTCs are present. If DTCs are present, the vehicle must be repaired and the codes cleared before performing the motor re-home function.
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  3. The entire brake system should now be bled following either the "Pressure Bleeding" or "Manual Bleeding" procedure outlined earlier in this section.
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WITHOUGH TECH 1®



This method can only be used if the ABS warning lamp is not illuminated and no DTCs are present.

Do not place your foot on the brake pedal through this entire procedure unless specifically directed to do so.

  1. Start the engine and allow it to run for at least ten seconds while observing the ABS warning lamp.
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  3. If the ABS warning lamp turns ON and stays ON after about ten seconds, the bleeding procedure must be stopped and a Tech 1® must be used to diagnose the ABS malfunction.
  4.  
  5. If the ABS warning lamp turns ON for approximately 3 seconds, then turns OFF and stays OFF, turn the ignition OFF .
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  7. Repeat these steps one more time.
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  9. The entire brake system should now be bled following either the "Pressure Bleeding" or "Manual Bleeding" procedure outlined earlier in this section.
  10.  

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Brake Specifications General Motors U Body

 
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