Rep Power: 0

I experience my brakes locking up. car stopped in the middle of the road. 1/2 hour before I can force move it to the side of the road. put on the new pads got home (about 7-miles) to the brakes locking up again, rotors red hot again. I bleed the brakes, took out again, and they began to slow the car down, I immediately returned home before they locked up on me. I then changed the Brake Fluid lines, bleeded the system, and the same problem continued, I then changed the master cylinder, change the rotors, and again the problem continued. I examined everything I had done, new pads, rotors, fluid lines, master cylinder, callipers and couldn't figure out what my problem was. I did a booster inspection by pressing on the brake, turning on the car and checking for the booster to work by observing the brake pedal slightly move. I search for the ABS system but the only line going into the brake system is the fluid line and nothing more. Does anyone know where my problem is.

 
Rep Power: 230

Very odd.

I would have guessed seized caliper or ABS error, but you talked about those.

When you have the new pads in does the hub turn freely? It should.

Is it possible that you didn't push the brake pistons back enough while installing the pads and there is friction between the pad and the rotor while driving?

 
Rep Power: 519

Care to disclose what car you have, exactly?

Which brakes lock up? Only front wheels? Both front wheels? All 4 wheels? One front and one rear wheel?

Any recent work done, shortly prior to this disaster?



Badly misadjusted brake light switch
Insufficient booster pushrod-to-master clearance
Contaminated fluid

 
Rep Power: 0

· It first did it with the original caliper, then continue doing it with the replacement calipers.

· I used a c-clamp to push the caliper piston all the way back, wheels did, and do rotate freely

· Only the front lock up, always the left, sometimes both left and right

· Before this began, no work was done to the brakes, I did a head job, engine runs great, car runs great.

· I know brakes are about to lock, when the brake pedal begins to get hard

· Not sure about ABS, only line going into the back of the brake assembly is the fluid line. No other line hard, or cable goes to the system, this baffles me.

 
Rep Power: 120

This is really weird. If the brake light switch or brake booster wasn’t adjusted properly, I’d think the back brakes would be dragging too. My best guess would be that the inside of the brake hoses are melted/collapsed and they are not allowing fluid to return, therefore the brakes don’t release. Next time the brakes lock up, open and close the bleeder valve on the locked wheels and see if the brakes release.

 
Rep Power: 519

Most of the time yes, but it still depends on how far out of whack it's gotten, and where the compensation ports are located. One section of the master cylinder can have it happen without any symptom the other.

Also consider the rears could also be dragging heavily when the fronts lock up, but if it has drum brakes it might not be readily apparent there's an issue happening.

Too bad we don't know what sort of car the OP has.

 
Rep Power: 120

 
Rep Power: 519

Consider it may be a conventional dual diagonal layout instead.
With rear drums. Unchecked, because they aren't smoking when he stops lol
And both sections of the master are affected, albeit one slightly before the other



If only we knew what kind of car this was......

 
Rep Power: 120

*Hint Hint*