Hi All,
Hoping someone here can help me because i am at a loss at this point. My brake pedal gets nice and stiff when the truck is of but as soon as i turn the truck on it goes to the floor with no to little pressure.
Here is what i have done that started this whole problem
1. replaced the rear drums and wheel cylinders.
After this i bled the brakes and messed up and let air into the front of the master cylinder resevoir (rear brake section) so i then was extremely careful not to let that happen again bled the brakes to get air out and bench bled the master cylinder. Again no air came out at the wheels, brake got stiff with truck off and then when started pedal goes to the floor.
2. I replaced the master cylinder with a brand new one and bench bled the new one and re-bled all the brakes for the 100th time and turn on the truck and again pedal goes to the floor.
I read that the power brake booster will cause the pedal to be stiff and hard to push not soft so i feel like it is working but not positive.. Also when i push the brake in the engine runs fine.. doesn't seem to want to die which i also read was a sign of a vacuum leak.
No leaks that i see anything under the truck and its been sitting in my garage while i work on it for 2 weeks so it would have been noticeable
i have read that could be the ABS that needs bled but that it requires a special scanner to do that.
Any info would be helpful if anyone has dealt with this before. EVERYTHING was working just fine before this (aside from needing rear brakes replaced) the brake pedal was working fine (for one of these old trucks at least)