I have changed the brakes, the master cylinder, the brake booster and bled out all the brakes and still have no brakes what else can I do?
RESPONSE
Try unplugging the ABS fuse or relay and test again. If you have no brake pedal after bleeding the system there is usually a leak. It may be an external leak or internal. An internal leak may be in the master cylinder or abs control unit. An external leak should be seen by fluid spraying out and dripping to the ground. You may need to bleed the system several times to get all the air out. Of course is this is an old truck, there would be no abs system to worry with.
BLEEDING ABS BRAKE SYSTEM
ABS system bleeding requires conventional bleeding methods plus use of the DRB scan tool. The procedure involves performing a base brake bleeding, followed by use of the scan tool to cycle and bleed the HCU pump and solenoids. A second base brake bleeding procedure is then required to remove any air remaining in the system.
- Perform base brake bleeding.
- Connect scan tool to the Data Link Connector.
- Select ANTILOCK BRAKES, followed by MISCELLANEOUS, then ABS BRAKES. Follow the instructions displayed. When scan tool displays TEST COMPLETE, disconnect scan tool and proceed.
- Perform base brake bleeding a second time.
- Top off master cylinder fluid level and verify proper brake operation before moving vehicle.