I'm fairly positive that I have at least one (passenger side) warped rotor. I just had new front pads and rotors installed in February so what causes rotors to become warped? Is it dangerous to drive with warped rotors? My brakes were making a lot of noise a couple of months ago so I had a friend check them out and he said the rotors didn't look to be the right size for my car, could this cause any problems?

 

As far as rotors not being the right size, I really can't help you. If your brakes are stock, then you should be able to go to a parts place (i.e. pepboys) and ask for a replacement set for your car.

Warped rotors is usually caused by extremely hard braking. This heats up the rotor too much, causing them to warp. Warpped rotors are not necessary dangerous, but will wear your brake pads down faster, may create uneven tire wear and will make the car shutter a little when pressing on the brakes. If you do replace the rotor, replace both fronts as well as pads at the same time.Shouldnt be much more than $150 I think.

 

i may be wrong, but ive never heard of anyone having warped rotors after replacing them with new ones only 6 months ago. I would bet that the problem is something other than warped rotors.

If you have warped rotors, you will feel an aweful vibration in the car when braking. is your symptom a vibration, or more of just a noise?

 

When I'm braking from doing over 50MPH, the car shutters back and forth and it can be felt in the steering slightly. When I get down around 5MPH or so, I can hear a creak coming from the front passenger side. It sounds like when you walk on an old hard wood floor in a house. If I take my foot off of the brakes completely, the noise goes away or if I stomp on the brake pedal, the noise goes away.

 

yeah, i guess that does sound like a warped rotor. Did they have any kind of warranty on them?

 

I had the car inspected a few weeks ago at the same place (my mechanic) that did the brakes. I told them about the noises and they cleaned and adjusted the rear brakes. Two of the three noises went away but this one did not. When I went to pick the car up after they did the work on it, when I was pulling out of the parking lot, there was a horrific sounding metal on metal sound that went with the rotation of the wheels. It got worse when I stepped on the brakes, but it went away after a few minutes and now this creaking sound is left.

 

The grinding sound that went away could very well have been the pads bedding themselves in the rotors; bedding the pads is something the mechanic should have done before giving you the car back, though.

Anyway, if the brake pedal and possibly the car is shaking on decel. I'd say you have some lateral run-out in the rotors (AKA "warped rotors"). You can either have them turned by a mechanic with a lathe or a machine shop or you can replace them. The general rule of thumb is they should only be turned once, but provided they can be turned and still be above minimum thickness, turning them more than once is a possibility.

As for the sound, I'd pull the pads off and put anti-squeal on the backs of the pads as well as the sides (the part that touches the pad holder part of the caliper). Make sure you don't get any anti-squeal on the friction surface of the pads.

And if you live in an area with a lot of hills or mountains, I'd say that's the reason the rotors are warping so fast (either that or uneven torque on the lug nuts). I used to live in the Appalachians (SW Pennsylvania) and went through brakes like they were going out of style.

 

Thanks for the info reaper2022!

I live in Maine and I do mostly city driving so the terrain isn't too hilly. The pads and rotors that came with the car when I bought it worked and felt great for the first year and a half that I owned the car. Those rotors never showed any signs of being warped. I'll look into having the rotors replaced, but I think its ridiculous that six month old rotors might need to be replaced. I don't brake hard unless I absolutely need to, so that can't be the cause of it.

 

No problem. I'm just wondering if a caliper isn't starting to freeze up. If one did freeze, it would wear out the pads and warp the rotor on that side fairly quickly. Have you noticed the car pulling to one side under hard braking?

 

Another reason why rotors warp is when you sit at stop lights or w/e for a while with the brakes pressed. Rotors are metal, they heat up and cool down a lot over time which causes metal fatigue by expanding and contracting. If you sit stopped with the brakes pressed for long periods of time while they are hot, the metal will warp ever so slightly in the spot the pad is making contact. Over time this effect will gradually become significant enough for you to feel the pulsating when applying the brakes. You say you drive around the city a lot which I imagine has a lot of stop and go which can cause the rotors to warp. 6 months is pretty fast though so maybe you got some really crappy rotors...