zena13

I posted this in the 2nd generation forum and haven't had much of a response. The braking system on my 87 looks similar to my 85 SE so I thought you guys might have some ideas. Anyhow, I have been having trouble with both front brakes dragging while driving at highway speeds. I notice a decrease in accelleration and the brake pedal becomes rock hard. They seem to free up when I am driving in town and using them alot.
What the heck would make them begin to lock up just driving down the highway without even touching the brake pedal ?

ioTus

iTrader: (5)

I have a similar problem w/ my GS,

And it also seems that the brakes pulse a little bit, too.

I attributed it all to the thought that perhaps one of my rotors was a little bit warped... not srue tho

Manntis

vould be the calipers are sticking in the brakes off position and the pads are worn, so at speed they're jamming against the rotors, and because the calipers are stuck they push back against the pedal...

...of course, that's just a guess off the top of my head and RevHed will probably prove me horribly wrong

zena13

It does have new pads and rotors. They begin to drag at highway speeds but continue at lower speeds as well. It seems like the more I use them the less problems I have.

Spieder

Standard disc brakes require the rotor to seperate the pads back off the disc. Usually there is no real back pressure restricting them from backing off that mm. It's possible you have a problem that's preventing the calipers from backign off. Perhaps a bent guide shaft or a malfuntioning piston. You might try replacing your calipers. They run about 40 to 50 bucks completely rebuilt from Kragen's, least for the 85's that is. Check to make sure those guides are not bent. Also make sure you don't have any clips that came out of joint and restricting movement.

zena13

I did check the movement on the guide pins and it is ok.
Actually I didn't have this problem till I replaced the pads and rotors. Could be the calipers but I don't understand how they could lockup with no pressure on them, just driving down the road.

Spieder

It's not so much that they have pressure, it's more that they can't get back off the brakes. Are you sure you have the right brakes. If they are too thick you could have a problem.There have been many a times I got the wrong plugs or brakes for my car and have to bring them back.

zena13

They are not always in the lockup mode. It seems that after I drive for several miles not using them they begin to drag. I t seems like something is creating pressure on them.

zena13

Any other ideas, Anyone !!!

Manntis

they slowly apply as you drive? that's peculiar.

I know many cars have a device that adjust the brakes as you back up, to take up slack with worn pads. That's the only mechanism I can think of other than the booster that slowly compresses the brakes, but for that to work in forward mode would be next to impossible.

If they were ovbersized pads, etc. you'd think they'd bind right from the start, though it may be noticeable only in a higher gear. With the high-torque military vehicles I used to drive, you'd occasionally someone drive for a few minutes with the park breeak on without feeling any drag (the smoke from under the chassis would give it away, as in that case the park brake was a drum brake around the drive shaft)

All I can say is double-double check everything, from your pads to the fluid level. If you recently installed everything perhaps a piece was omitted?