Shelty

when you hit the brakes on my '91 there is a good deal of vibration as the car slows to a stop, first I thought it was bad rotors/pads, well the rotors and pads turned out ok, rotors are not warped, nor are the pads irregularly worn, in fact they are almost brand new.I'm now thinking that the tires are out of balance, or my alignment is bad.

also the brakes are a little soggy, not too bad, but can get a bitscary when some idiot pulls out in front of me at the last second....could this be out of adjustment brakes or could this be that my drums need to be serviced (I have no idea how to do them.....) and when you hold the brake down it makes a hissing sound for at least a minute. I checked for leaks and bad vacumn lines, but everything checked out good...

1985stang

It wouldn't be the tires or alignment if you only feel the vibration when you hit the brakes. Did you check the drums? They can be warped also.

mjr46

how do you know your rotors aren't warped??? brake pulsation when applied is usually an indication of warped rotors....do you feel the shake in the steering wheel when braking???.......if brakes are spongy feeling you may have a leaky wheel cylinder or air in the system due to a leak and or the rear shoes could be worn and frozen adjusters in the rear not allowing the rear to self adjust properly and a quick check of trying to adjust the rears manually can rule that out...you however may have to knock out the factory tack welded plate if no one ever has...the hissing could be a leaky brake booster..a smoke test can test that out quick if you have acess to such a machine

Shelty

it only vibrates excessively when the brakes are applied hard, light brake pedal pressure doesnt cause much pulsation. I have a set of powerslot rotors, new calipers, two wheel cylinders and a full bearing kit for the front wheels, just dont have time to put them on yet. I do know the wheels need to e aligned as the tires are worn more on the inside, indicating either bad camber or an alignment...

I just assumed that the rotors were ok cuz the pads are worn normally and they didnt look to have irregular wear and they werent uneven....

and I dont know what a smoke test is, and I have not checked the drums

1985stang

Haha, so did you even feel the rotors to see if they felt warped? Oh well, it doesn't matter anyway because you got powerslot rotors you lucky b**** . You should check the drums though.

slickshift

Vibration only when slowing from hard braking, or slow braking (not from high speeds) could mean rear brakes out of spec (warped drums or other nastieness)
Those are the times the rears really come into play
Worth a check anyway

While your at it, give the system a good bleeding

Sort of sounds like a leaky/faulty booster though
Not going through fluid or anything?

mjr46

you can't usually see a warped rotor or visually tell by feel either...the only way to tell with slight warpages is by using a dial indicator mounted on a stationary surface on the suspension and checking for run out.....anyway my guess would be on warped rotors and or drums...sounds like the brake system on your car needs a complete overhaul

Shelty

It prolly does, I mean the thing is 16 years old, and who knows what its been through. I'm not using up any fluid, never see any fluid on the ground, or anywhere under the car, which I guess is a good thing. I'm gonna have to go through it when I am home from college, as I cant work on my car in my apartment's parking lot, I'll have to have the drums done by my mechanic as I dont like them, I did them on my old buick once and it took me forever to get them apart and together. I hate doingthem....

wish I had enough for a 4wheel disc conversion