brake trouble, front brakes lock when hot Options

[trfrick]

I need some help - I replace the front rotors, calipers, pad, flex line and m/c. Now when I went for a test drive after several hard stops the front brakes get hot and lock up.
After they cool they release.

What should look for?

Thanks
Tom

[toolguy]

The bad part is you replaced a whole bunch of stuff, any one of which can cause problems . . . It sure sounds like you don't have pedal freeplay . . are all the calipers and the MC new? or did someone rebuild them ??
are you sure you're starting with known good units ?? If you're not sure, it's like shooting yourself in the foot. . .

Lets get to basics first for trouble shooting,

When the master cylinder is in the released or at rest position, you should be able to pry back each brake pads. . . the fluid you're compressing in the calipers goes back thru the uncovered inlet port in the master cylinder up to the fluid reservoir. . . If you can do this, then there is no mechanical reason why the pads when the pedal is released can't do it themselves. but your statement about only when hot or cold makes me think something is expanding when hot and binding. .
If you cant push the any of the pads in , my first guess is the master cylinder probably has the rod depressed and the piston is past the port hole for whatever reason.

When it's working correctly, as you step on the brake, the MC piston covers the inlet port, sealing off the reservoir, and forces fluid out to the calipers. . not back up to the reservoir, making it a one way system, but only if the piston port is covered.

If you can pry back any one, then the MC port is uncovered. . . . . Next, Make sure your can pry all pistons back. . . it should take only light force. . . you may have sticking pistons but I can't imagine all 4 sticking at once . .
Do all the pads fit in the calipers easily, do the move freely ? or do the rub and bind on the caliper ??

If you can move all the pistons, you might try putting your old pads back in a see if the problem changes. . that's easy. . . If that doesn't do anything and you're still puzzled, put the old MC back in. . that's a pain ion the butt, but there isn't anything else left to change. .

Just remember, you're going to solve the problem, it's just a matter of the steps you have to go through to get there. .