Brakes locking up after short drive

[jefftobrocke]

I'm having issues with my front brakes locking up to the point where the car is not drive able. I just took it out for a short ride and by the time I returned to the shop the rotors were glowing! I've replaced the booster and master cylinder. Bled al. The way around, greased the slides, new fluid. It was limited to the right side front prior to the master cylinder replacement and now it's both fronts. Started out with no binding and all of the driving was flat road. Need some help. Have I not adequately bled the system. The previous owner had similar issues and replaced the calipers and wheel cylinders. Could it be a vacuum issue with the booster. The pedal seems way too hard.

[So Cal Mark]

it sounds like the pushrod between the booster and master cylinder is misadjusted, keeping the piston too far forward in the master cylinder. Loosen the nuts holding the MC to the booster and see if that releases the brakes

[divace73]

it sounds like the pushrod between the booster and master cylinder is misadjusted, keeping the piston too far forward in the master cylinder. Loosen the nuts holding the MC to the booster and see if that releases the brakes

+1

[jefftobrocke]

Nope, adjusted and within low end of spec. What about interally colapsing hoses?

[NSFIAT]

I had to adjust mine outside of original spec - it was a new unit purchased from AR. No issues with stopping power and the pedal feels fine.

[GeorgeT]

I had a similar problem and it was a collapsed brake line; when the brakes were applied fluid was pushed into the calipers and brakes were "on" but when the brake peddle was released an internal collapse in the brake line acted as a one-way valve and prevented the fluid from returning and the brakes stayed on. This was on my rear brakes, not front.

[So Cal Mark]

if loosening the MC doesn't release the pressure, open a bleeder and see if there is pressure. If that releases the pressure then you have a bad hose or restricted hard line

[jefftobrocke]

Hoses are easy replacements and inexpensive, should I replace the hard lines while I'm at it?

[So Cal Mark]

not unless they're damaged or don't flow fluid

[jefftobrocke]

I believe the problem has been solved, I installed new hoses on both front calipers and the brakes are working as they should.