Warped Rotors

[97GreenGTP]

I have a 97 Grand Prix with 216,000 miles. I have replaced the rotors and pads about a year ago. They got warped and i got them turned. In few months, they got warped again. The mechanic tells me that I brake hard, which I dont. I am the only driver of the car. Can anyone think of an other reasons for warping of the pads in such a short time? I haven't replaced any brake lines or anything else in the braking system.

Thanks in advance.

[tblake]

Take a drive for 10 or 15 minutes and just stop and accellerate as you normally would. When you park, get out and feel all 4 wheels. Feel if one is hotter than the rest.

i had an issue where one caliper was hanging up and constantly applying pressure to my pads/rotors. Even with no braking this caliper applied the brakes thus overheating the rotor and warping it. replacement of the caliper cured the problem.

Maybe your issue is like mine?

[BNaylor]

The question I have is what brand rotors and pads were installed? It is not uncommon to get warped rotors after having rotors turned down instead of replacing them again.

And was that on all four wheels?

[97GreenGTP]

I think they were AC Delco rotors and pads. I don't remember which quality grade (expensive) they were. I have been having this problem for a while. When I installed the last set, it was because the previous ones were warped too.

It only happens on the front wheel. May be the front wheel is doing all the braking. Do you think hydraulic pressure distribution might not be adequate between front and rear wheels? If that is the case, how to detect it and fix it?

[richtazz]

Another question. Did you put the brakes on yourself, or did you take it to a mechanic? If the lug nuts aren't torqued to spec with a hand torque wrench they will eventually warp over time due to the uneven clamping force. Do not trust those "torque sticks" that garages try to use attached to their impact wrench, as they do not work and are highly inaccurate. I had 2 front tires put on my wife's mini-van, and they used those torque sticks to put the wheels back on. I checked them when she got home, and on one wheel, 2 of the lugs were barely tight and the other 3 I needed a 4 foot pipe slid over my 3 foot breaker bar to get loose. The other tire would have probably soon fallen off as 3 of the lugs were barely snug, so loose that just the weight of my torque wrench handle turned them.

[BNaylor]

Originally Posted by 97GreenGTP

It only happens on the front wheel. May be the front wheel is doing all the braking. Do you think hydraulic pressure distribution might not be adequate between front and rear wheels? If that is the case, how to detect it and fix it?

It is best to do all four at the same time. If the rear brakes are worn out braking balance is affected and the front have to work harder regardless of the built in proportioning system.

[97GreenGTP]

I told my mechanic to look for all the problems suggested by great guys like you and guess what, seems like it helped. He told me that the calipers were sticking going in and coming out and also the bracket on which caliper mounts was sticking to the pin. He opened the bleeder valve and return pressure was OK, which told me that the lines are OK.

So he replaced the rotors, pads, calipers and brackets and hopefully it solves the problem. Atleast for now, I have nice smooth breaking.

Thank you BNaylor and Rich.