need help with rear brakes!!!!!!

[old_blue]

I just replaced a friends rear disc brakes (98 v-6). He had worn them down to metal and both rotors had to be replaced. So we got new pads and rotors everything is fine. A few days later we start to hear a harsh rubbing sound while the car was rolling, if you step on the brake a little bit the noise goes away. So we got home and i started to take the rear passenger tire off and the bolts are HOT!! i checked the other side and there were warm but you could hold them in your hand. the passenger side couldnt be touch. Well, we got them off with the wrench pulled the wheel off and I ran my finger across the rotor (yeah I knw not too bright) it blistered my finger. They must have been rubbing the whole time. SO I am assuming the rotor is warp but cant figure out why. They were both brand new. the driver side seems fine.. could the caliper be done in??? I thought if they went bad they usually locked in place. Both went in with no problems.... anyone got any suggestions???
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[HISSIN50]

you are on the right track. i would check the caliper. was the piston harder to retract than the good side?
also, the pins that the caliper floats on have to be nice and clean. if the caliper cant float, it will ride (the pads stay engaged against the rotor).

remember, when one pushes the brakes, a lot of hydraulic pressure pushes the pads against the rotor. when the brake is released, there is not an opposite force retracting the piston to get the pads off the rotor. add to that, that if the pins are cruddy or bent, the caliper cant slide (so the outer pad stays against the rotor).

do also recheck the general suspension. a bad ball joint, etc can throw the dynamics off and create a lot of heat.

my two cents. good luck (do be sure he fixes it before driving - brakes are one area not to drive with while they are compromised).

good luck.

 

[old_blue]

hmmm, i must confess that I did not know that the pistons retracted by turning versus the style I am used to which is pushing it in. So I tried the piston tool first and it didnt work so that might have bent the piston. although I did try harder on the one side versus the side the is sticking. I guess that messed up the piston. Thanks for the reply .

 

[HISSIN50]

hmmm, i must confess that I did not know that the pistons retracted by turning versus the style I am used to which is pushing it in. So I tried the piston tool first and it didnt work so that might have bent the piston. although I did try harder on the one side versus the side the is sticking. I guess that messed up the piston. Thanks for the reply .

it can go either way. some pistons can be pushed back. if they dont, there is a chance they turn in. ive had turn-ins on older european cars, but did not think they still used them. the screw in pistons i had, had a flatblade screwdriver slot in the center of the piston, so one could screw them back in.
i would bet that the pistons simply push in. a repair manual pic/write up would confirm this (or search in the later model 6 banger subforum or whatever is appropriate).

so if it was that hard to get them back, i might look there. the thing is that if the carrier pin (the pin the brake caliper slides on) is bent, etc (see previous post), the binding can cause so much heat that the caliper warps, the piston distorts, etc (causing a sticky piston, like it sounds like you had). it would be hard to bend a piston, i think. it is just a slug in a bore - it can rotate.

sorry i dont know more about the newer model brake set ups and what they use exactly.
good luck.

 

[ratrapp]

yes it does have screw in calipers that need to be twisted in place.they do fail often as it is the same design of the taurus rear discs.do as hissin said and check your caliper slides as they do rust inplace right often.they make caliper slide grease to lube them.if this doesn't fix your problem it may be a bad caliper or brake hose thats not releasing properly.

 

[BlackFox5.0]

Whenever you do disc brakes, always check the slides to make sure they move frely, if not then remove them and if needed replace them, but always lube them up good. I use a product called Silglide to lube up the pad mounting surfaces and slide pins. Like said above, make sure the piston is turned in all the way.