GMC Truck Forum banner
1 - 1 of 1 Posts

·
Registered
Joined
·
2,825 Posts
ABS box is bad in every 99-02 GM truck. They don’t affect braking performance. Just no anti lock. And sadly they never take an auto bleed because of the anti lock code.

Take the intake line off the booster and drop a zip tie in to check for fluid inside. Old truck it may have some. If it’s half way full, R&R master cylinder and booster. If not move on.

Start at the highest point and work down. Meaning the master cylinder. Crack the lines, if you get a steady drip out the lines, close and move to the calibers. If not R&R master.

After that I personally like to run clear line from the caliber bleeder back to the master cylinder one at a time then pump the brakes till it’s solid fluid. Close and move to the next caliber, unless you find a issue. Honestly there’s about 100 ways to do that, air bleeders, vacum pump, helper, or just gravity.
 
1 - 1 of 1 Posts
Top