Front nor rear brakes a grabbing on this chevy S10 (1991)?

Question

I replaced the lines on this truck. Even after i bled the brakes on the rig the front disc. brakes and the rear drum brakes are still not working. What could be causing this, i checked the master cylinder and it is working, problem? How can it be fixed?

Answer 1

Did your brakes work Ok before you replaced all the lines? What problem did you have before the lines were replaced. How is the brake pedal? Hard or spongy? Does the brake fluid come out strong when you bled the system? Need more info to determine your problem without seeing it. I am beginning to suspect that there was a problem before and you didnt mention anything about the proportioning valve. This valve distributes the pressure of the fluid to the front and rear brakes. You may need to bleed or replace this valve. You still have a lot of air in the system. Have you bled the master cylinder too? This is the starting point, bleed the master to get pressure. Then crack loose the lines from the porportioning valve and check the pressure and if there is air inside of it. Bleed this too. If you cannot get this valve to bleed or push pressure, then replace it. Once you get pressure from the valve, now you begin the entire system bleed starting with the wheel furthest from the master, RRear 1st, Lrear 2nd, RF 3rd and driver side front last. This should do the trick and a lot of DOT 3 brake fluid.
Good luck............e-mail me if problem is still there.

Answer 2

YOU NEED TO BLEED ALL THE LINES STARTING WITH THE ONE FARTHEST AWAY FROM THE MASTER CYLINDER (PASSENGER REAR) THE DRIVER REAR THE PASSENGER FRONT THEN DRIVER FRONT IF YOUVE CHECKED THE MASTER CYLINDER THEN THE ONLY THING LEFT IS THE WHEEL CYLINDERS AND CALIPERS

Answer 3

check all your vaccuum lines, it could be one has a hole or has come off, simply repace the hose or hook it back up.