Another brake issue thread

About a month ago my rear brakes were taking turns locking up. sometimes my RR and most of the time my LR. Anyways, I replaced the calipers, pads and rotors. I only had to use the ebrake once about a week after this was all done. Everything was great until i was about 30 miles into my 35 mile drive(straight highway) to work this morning. I started smelling burning brakes. When i got off the highway smoke was coming from the LR and the tire was squealing intermittently. I had it looked at at work and they could see it was locked up but it seemed to bleed ok. but no one could give me a straight answer. they pointed something out to me and said they thought it was the problem but they werent sure(see picture here http://i4.photobucket.com/albums/y127/dazeyc/05-22-05_1858.jpg) and they didnt know what it was called either, just what it does. anyone have any ideas what this part is called and wether or not it could be the problem?

Almost forgot...it's a 93 Eurosport sedan :loser:

I don't think that's the problem. ABS can't apply pressure to the brakes, only modulate the pressure you supply. I'd be leaning towards collapsed hoses in the rear, if all the other hardware checks out.

Have you flushed the entire braking syatem? Occaisionally, you'll see very badly moisture-contaminated fluid vaporize under normal operating temps, and apply pressure in the system.

My friend had one of those GM's with the wonky rear disc brakes, he was going down the highway when the LR rotor disintegrated from heat fatigue, setting the tire, wheel, and caliper free, and shrapnel destroyed the strut. What was left of the lower suspension was damaged in the prolonged drag from the left lane to the shoulder. Be careful till you figure it out.

we flushed the brake system when we replaced the calipers, pads and rotors. we dont think its a collapsed hose because they are bleeding just fine. no restrictions. someone told me to try and replace the master cylinder and metering valve but thats kind of expensive for something that may or may not fix it. right now its parked. i refuse to drive it because it scared the crap out of me. so my boyfriend and i are fighting over the pontiac :biggrin:

we also replaced all the rear hardware when we did the brake work

Bad hoses won't do their thing when you're bleeding them a lot of the time. You have to take the car out and use the brakes until the wheel starts dragging, then right away get out and crack the bleeder (without pressing the brake). If a shot of fluid flies out, and the brake relaxes, the hoses are the problem.

When bleeding, there is little or no "return" flow happening in the hose, as you are relieving the pressure through the bleeder. When fluid pressure tries to back OUT of the caliper is when the restriction occurs. Fluid flow TO the caliper is almost never restricted.

When hoses fail in this way, a portion of the inner layer is acting as a one way valve, allowing pressure to the caliper to apply it, but restricting the flow outward, holding the caliper engaged.

As short as the rear hoses are, if they are twisted or stretched at all during brake work, that is often enough to make them come apart internally.

Just thought i would update on my problem. im pretty sure we've figured it out. one thing that i noticed when the brakes locked up, when i removed the cap for the master cylinder, the rubber seal would be pulled down. when i removed the seal, theres a vent type thing built into the cap that seemed to have some sort of gunk in it. i cleaned it out really good and have been absolutely problem free since(a few months)...thanks for replies :biggrin: