My '76 Bronco just received a '91 5.0 EFI engine. The brakes worked normal before the swap. The brake system lines were never disconnected and the whole system was left completely intact during the swap without any leaks of fluid. The MC was disconnected from the booster to paint it but the hydraulic system was never opened.
During the first test drive the brakes were not performing correctly. I would press the peddle and I would not feel the brakes until I had the peddle almost to the floor, and then with added foot pressure I would get full brakes all of a sudden.(locking up the front brakes).
I then took the MC off and adjusted the stud on the end of the push rod from the booster 1/4 turn. Took it for a test drive and no change. Adjusted 1/4 turn again, test drive, no change. Made a full turn, test drive, no change.
Then we bled the brakes. Started in the R rear, pumped the brakes,hold, opened bleeder, peddle drops with out much pressure from my leg, and fluid steadily pours out without bubbles. Repeat the bleed on L rear. Same result.
Bled the R front. Pump, hold, open bleeder and not much fluid comes out, I push the peddle harder with the my leg and with the valve open and fluid starts gushing out. Bled the R front a few times and it showed the same symptoms. Tried the L front same thing happened, pump, hold, open- not much fluid comes out, push harder fluid gushes out.
I have a stock peddle assembly, booster,brackets and linkage, new MC, new proportion valve,new front calipers/pads, new front SS lines, rear is stock drums with a slight wheel cylinder leak in the left rear, and original steel lines.
Does anyone have any ideas on what would cause this problem and how to fix it?
During the first test drive the brakes were not performing correctly. I would press the peddle and I would not feel the brakes until I had the peddle almost to the floor, and then with added foot pressure I would get full brakes all of a sudden.(locking up the front brakes).
I then took the MC off and adjusted the stud on the end of the push rod from the booster 1/4 turn. Took it for a test drive and no change. Adjusted 1/4 turn again, test drive, no change. Made a full turn, test drive, no change.
Then we bled the brakes. Started in the R rear, pumped the brakes,hold, opened bleeder, peddle drops with out much pressure from my leg, and fluid steadily pours out without bubbles. Repeat the bleed on L rear. Same result.
Bled the R front. Pump, hold, open bleeder and not much fluid comes out, I push the peddle harder with the my leg and with the valve open and fluid starts gushing out. Bled the R front a few times and it showed the same symptoms. Tried the L front same thing happened, pump, hold, open- not much fluid comes out, push harder fluid gushes out.
I have a stock peddle assembly, booster,brackets and linkage, new MC, new proportion valve,new front calipers/pads, new front SS lines, rear is stock drums with a slight wheel cylinder leak in the left rear, and original steel lines.
Does anyone have any ideas on what would cause this problem and how to fix it?