LWillmann

What's got to be happening then is that there is more pressure pushing the caliper piston on the driver's side causing it to grap harder/all the time.

That leaves the lines from the calipers to the ABS unit to check.

The constant pressure on the rotor is probably causing excessive heat which is warping the rotor.

anasazi

bearings seemd fine, didn't have any play in them.


what between the caliper and the ABS unit would cause it to grab like that? both sides bled the same when we bled it with the car off.

could the ABS unit itself give us these problems?

anasazi

bump for the night crowd

bdc95ta

with new calipers that shouldn't be happening the pistons should be hitting equally on both sides. I don't know about this one if your, pistons are (new), aliment is good and your control arm bushings and ball joints are good. Then perhaps it's a loose wheel bearing, which could cause the wheel run out to be exessive and can knock the caliper pistons farther back. Which would increase braking travel and cause uneven braking and a pull to one side. A loose steering linkage could also cause the brakes to pull. One way to tell if it's your front or rear brakes is how much the wheel turns when braking. If it's your rear it won't turn much and probably only under hard braking; if it's your front it will happen even w/ light braking and the wheel veering will be quite strong. Any more info. you can give us?? did this happen before you messed with the brakes, has the car been in any wrecks???
-b

slopokrodrigez

Did you look at the back brakes? One thing to try is to brake in a parking lot with the emergency brake only. This will give you an indication of what the back breaks are doing.

Apply a small amount of antisieze to the caliper where the 2 halves meet. Not on the studs.

If all that still doesn't help the last thing I can think of is to take a pressure reading at each caliper.

anasazi

car hit a curb earlier this year... enough to destroy a rim, but not to seemingly bend anything as the alignment is fine.

when i used the e-brake it stops in a straight line.


when you say put antisieze on where the two halves meet, where are you thinking of? the calipers are cast iron beasts with a single piston, are you talking about on the piston?

2MCHPSI

Try looking at the proportioning valve.

thermwood1

When you bled the brakes did you just do the front 2 and did you bleed the one furthest from the Master Cylinder first?

anasazi

we bled it ABS first, then rears, then fronts, starting with the farthest away. when we tested to see if they bled the same, we just did the fronts (as there was no air in the system).


where is that? and would it affect just one side of the car?

slopokrodrigez

I'm talking about where the 2 slide in and out. There is a mating surface where both halves of the caliper touch. But I don't think it's a caliper problem cause you would hear the brake rubbing all the time.

I don't think it's a proportioning problem cause they work front to back I don't think they work side to side.

The rim that was bent, was it the left front? Is that when the problem showed up? If so you bent something, or broke something you didn't find yet. It's not an alignment problem caused by the bent rim incident or you would feel something all the time not just braking.

You recently changed tires due to wear didn't you? If so how are the new ones wearing. I think your left side is moving fore and aft. Before I waste any more time, I would get a pressure reading for both the front brakes. If that turns out to be equal, then have a different frame or alignment shop look at the front end again.

jasons93z

I have to agree, it does sound like a suspension problem to me. Back when i had my truck, it did the same thing. The cause of the problem was that the endlinks on the swaybar had popped, go figure

anasazi

alignment is fine. both sides of the car have the same measurements. i have the printed out paper of my alignment in my car so its verified.

i rotated my tires, and its still pulling. wear seems about even so far, a little more on the right side i think.


its not suspension i don't think, because the drivers side caliper (the side its pulling torwards) is always grabbing the rotor. it is much warmer than the passenger side and is noticably harder to turn when you have the wheels off the front of the car.


i hit the curb back in feburary. i don't think this is when i started to have a problem. it hit on the passenger side, cracked the rim but didn't blow out the tire and didn't seem to bend anything (alignment is fine). also distroyed that wheel bearing over time, so its been replaced.



what really is confusing us is that the drivers rotor was very warped, and once turned we took the car out on the road everything was PERFECT ... for a few hours of driving and now its back to how it was in the first place.


we didn't notice any play in the wheel bearings, however could there be play that just takes more force than we can exert with our hands? such as driving? maybe this would position the caliper and the rotor in such a way so that they were possibly hitting, causing the rotor to warp enough so that the caliper will always hit it?


also, how are the front brake lines seperated? is it one line from the master cylender then it splits in the ABS module?


could i switch the wheel bearings to the opposite sides? once used can they be switched so that they rotate the opposite way?

thermwood1

Not sure about the wheel bearings, but you said that after the rotor was turned you took the car back out and it drove fine for a couple of hours. Is it possible that the rotor warped again? Have you had this checked out? Maybe the rotor is too thin now or there is some inherent problem now with the rotor material itself.

slopokrodrigez

There should not be brake drag when you rotate the wheel. And as Thermwood said, it's probable that the rotor has warped again. You should put brand new pads and rotors on and lube the caliper so it doesn't stick. The reason for the new pads is to be sure of thickness. There are less expensive alternatives to OEM rotors.

scooters97ss

You should check the steel brake line to see if it wasn't flattened out a little when you mashed the wheel. If so it will hold pressure on the caliper. Try pinching off the front flex hoses (with the brakes released) and driving the car. This will either eliminate or single out the front brakes. I would also have a professional closely recheck the front end. Tell him the whole story on the car; IE: curbing it; what you've done so far; etc. I would closely check the control arm bushings and ball joints on the side you mashed; just because the alignment is ok sitting static on the alignment machine doesn't mean that it is the same out on the road under heavy braking. Trust me- I'm a front end/brake specialist so I see stuff like this all the time. I have seen instances where there is a problem with ABS controllers and valves but they are very rare and USUALLY do not act like what you are describing. Good luck and keep us updated.