ok so last year i had this same problem of the brakes locking up. Just this morning i put 4 new calipers and rotors on the truck b/c my old calipers (that are less than a yr old) seized up and wouldn't let the truck move, also the actual pistons broke apart.

So i put everything new on and bleed the brakes it seems like the fronts are locking up again. So after just spending almost $500 bucks on everything i have the same problem again.

I'm thinking maybe it's the ABS module.

anybody have any ideas. i'm about ready to burn this thing.:mad:

thanks in advance
kyle
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Are you sure the hydro boost isn't causing any problems


We had a truck at work that would lock the brakes when you turned the wheel:eek:

well it's not leaking or throwing any codes. i guess a tech II would be able to read into it though. Only reason i say module is b/c last year i had a brake line ground out on the frame i think maybe that might have done something to the ABS module.

to asnswer your next question, when the brake line hit the frame it sparked, i think it was because i was missing a ground going from the frame to the motor.

Last year, my retired father, calls me from FLA. He's sitting on the side of the road, in his 2003 Chevy van, with the brakes locked up. He tells me this has been happening on and off for three weeks. I think the same thing you did, ABS right?? Then I realize, the ABS can only release the brakes, not apply them.
I call my buddy at the dealership, he asks me if my dad has had the oil changed lately, at a quickie lube joint, knowing my old man , I answer "probably". My buddy says, that's the problem, the quickie lube joint mistakenly added power steering fluid, to the brake master cylinder. Both fluids are clear, and easily confused.
The power steering fluid, expands with heat, and the expansion applies the brakes. I called my dad back, sure enough the problem started right after a quick lube visit. He had it towed to a dealership in FLA, they pulled a sample of the fluid, let it stand, in a clear plastic bottle, it was obviously, two different fluids.
They flushed out the fluid, replaced the master cylinder, charged my dad $600.00, and the brakes have been fine every since.

If I were you, I would flush out the brake fluid, it may be contaminated, with something that is expanding, when heated.

I would agree even water in the fluid will do that.
What brand were the calipers you put on last, and what brand now?
Did you replace the rubber lines? They could have colapsed.
How about the slide bolts? Did you clean and grease them or replace them? Should cause all of it but will contribute.
Also had a coworker with an 04 put anti-seize on his slide bolts, swelled the bushings and wore his pads down along with the brakes staying somewhat applied.

well i did drain all the fluid out and put new in, it took 2 whole large bottles of brake fluid.

not sure on the brand, just some off the shelf deals from some place in KY last year and Advance onces this time.

i have stainless braided lines all the way around.

i changed the bolts both times i did the calipers and did grease them.

get this now though, last night everything seemed fine on my way home after i took the ABS fuse out. This morning i hit the pedal and it goes to the floor after a sec or so. I get here and look and the ms is still full, if you hit the brakes you can see the fluid go down a bit then come back up like normal, yet the pedal still will go to the floor.

Sounds like air in the system. If the fluid still clean? If it's dark it has water in it. Could have evaporated the water and created an air bubble.

nope clean as a wistle. someone mentioned that it could be bypassing inside the MS. he told me to block off the lines and push the pedal, if it still drops then it's the ms.