My 1995 Chevy Surburban began losing its brakes (air in the line symptoms-would not hold). I had the Master Cylinder Replaced and it worked for a few days but then needed bleeding again. After bleeding it several times just curious what the problem could be or what we could try. Appreciate your time and expertise.

thanks Boanman

 

Hi Boanman,

Welcome to the Chevy Forums.

Did you bench bleed the MC?

If not, try this. Jack up the back end of the truck until the brake fluid is level in the master cylinder. Carefully block and support the back end. Then take the brake lines off the MC and screw in the bleeder tubes.

You should be able to look through the open hood into the MC, if not have somebody else hold or watch the bleeder tubes as you pump the brake pedal 10 - 12 times. Refill the MC. Lower the vehicle. Re-bleed your brakes. Test run the vehicle.