My brakes sometimes get really tight while driving especially at 60+mph.
here are the symptoms:
1. The steering wheel shakes vigorously at 60+mph.
2. The car slows down rapidly when I ease off the throttle.
3. The front right rim is super hot, i can smell burnt brake pads.

What could be the problem? It disappears when I turn the car off and pump on the brakes (works most of the time). My car has 200,000 miles on the body and has a new brake cylinder and new calipers.
Please help!



[Modified by ibp4da97, 7:11 AM 5/29/2002]

 

I would try bleeding the entire brake system. It should help.

 

I've done that... still the same problem though.

 

i dunno....go to a shop and get a complete diagnostic brake check. it'll tell you everything that's wrong. is your brake light on in your car?

 

The shaking could be from warped rotors.

 

Or a siezed caliper.

Miguel

 

One bit of advice: Don't drive at 60MPH if your car reacts so violently. It sounds like your car is braking while you're driving. Like something is pushing the pad onto the rotor. My best guess is that it's not bled properly, or that the pads weren't installed correctly.

Does the car want to pull to the right? If so I think that your right front brake is engaging.

 

Does the car slow more rapidly with the foot off the gas than before? If it is the same as before, you have warped rotors. Also if the brakes are new, some manufactures have certin break in periods.

 

The car does slow down more rapidly than it normally would. The calipers are new, the rotors have been resurfaced. I definitely know that the brakes are engaged at times because I can feel it. We've bled the car (cris-crossing front left side first, rear right second, rear left third, front right last). My brake master cylinder is new (oem part), the brake booster valve works, but I haven't checked the proportioning valve and the booster itself. Could this be the culprit?

by the way, thanks for the replies

 

Here's 2 more thoughts to consider:

1) The piston could be seized inside the caliper or maybe it can only return to a certain point. Was it difficult to slide the caliper over the pads when you reassebled it?

2) Since it's a floating caliper, you've got to be sure you've lubricated the caliper pin. If not, it will stick. It's happened to my rears on a couple of occasions.

Assuming you're using the same propotioning valve, my guess it that it's ok. Are you using a replacement booster or on from a different car?