Hey guys i have installed a set of ac delco drilled slotted rotors cause my old ones warped... problem is this i have had them about 6 mos and already have had to turn them once because of a pulsation at freeway speeds... now they are warped again i have checked the rear calipers and the slides seem fine and the pistons arnt stuck (pushed them in a bit with a c-clamp) and the brakes dont pull when stopping... i dont drive the car hard at all and the pads im using are raybestos low dust ceramics!!!!! is there anyone out there that can help me fix this perminatly?

 

Are you saying the rear brakes are warping? If so, that's a new one on me. Bet you have an automatic tranny. If the rear is the problem on your car, you could have a bad proportioning valve. Did you do a break in proceedure when you changed the rotor and pads?

The only way I finally got rid of the problem on my 99 chevy pickup was to get crossed drilled rotors and after they warped the first time, had them turned and they have been ok since. I have heard that a lot of rotors are slightly warped when they are new. Not sure though I never checked.

Always a good idea to bleed the fluid completely at all the calipers to get new fluid in the system at least every 2 years. DO NOT save fluid to use later like in a half full container. If you don't use it all, toss it. When you do the job, buy new fluid when you need it and chuck the left over.

BTW when ever you do pad work, it's a good idea to check the condition of the piston and O-ring. And always turn the rotors or drums.

 

I see several issues-

1. cross drilled. MUCH more likely to warp and crack-

2. Ceramic pads. Who in their right minds suggested ceramic pads for a daily driven car. You REALLY have to heat those things up before they start to be effective. Do you do a lot of autocross/road racing?

Want to stop fast? Hawk or similar pads and blank rotors. And to boot they will last longer and cost less.

 

not true. you dont always have to turn a rotor- and in many cases you shouldn't. I dont know much about turning but
I do know that most of the time a mechanic cant not get the rotor into spec. Thickness variation on a rotor is somewhere in the neighborhood of about 40 microns. anything more and you slowly start "pulsing"

Also, turning an already fragile cross drilled rotor is a bad idea IMHO.

Im not a big fan of turning but do what budget allows.

Im a big advicate of skrew the bling- get some blank rotors that will stop faster, last longer and cost less.

 

no autocrossing just daily driving too and from work... as far as who sugested ceramic pads??? call it my own fault cause in reading hot rod mags and so forth and then the lil advertisements that raybestos puts in certain mags i assumed that using their less dust or no dust pads was a good idea... also its my right front that has warped (put them both on a lathe the other day just to check) this is the second time in 5 mos!!!! i dont know why they are doing it but its starting to get annoying

 

are you SURE your caliper is ok? uneven force application will cause problems.

cross drilled will have a much higher tendancy to warp. go buy a set of QUALITY blank rotors.

I might be wrong about the pads- i'm 90% sure they are a bad choice for daily driving

 

i pushed in the calipers with a c-clamp and they seemed to not be stuck... i still have about 800 miles on the extended warranty maybe ill just have them replaced (i can make them leak if need be) and can try that... im just tired of always having to fix it for warpage so NO im not 100% certain they are ok i just have used the normal checks to see if they are stuck