S197steve

About three or four weeks ago my buddies and I installed new pads and rotors on the front (ATE rotors & Hawk pads) from Strano Parts (great service and pricing BTW). We also rotated the tires at the same time. Since then, the car has been tram-lining quite a bit, pulls to the left and generally feels quite twitchy. I tried ‘un-rotating’ the tires and put them back into the same position prior to changing the brakes but that hasn’t helped at all. Prior to the install the car had a very slight pull to the left, but not nearly as bad as it is now and wasn’t twitchy. The brakes aren’t binding and the tires (Hankook Evo Ventus) are all directionally correct and have no wear issues at all. The weirdest part is that it seems to be worse when it’s cold out (sub 40s) but my cold tire pressure is OK at 32psi on all four tires. I’m at a bit of a loss here and was hoping to get some help.

The only thing I can think of is from a thread I read on here a LONG time ago: The situation was that folks were having twitchy steering issues when they swapped wheels and removed a clip on the brake caliper or something like that. The roads I drive on have some rough patches, but I don’t think anything out of the norm (huge pothole or bump) has happened since the install. I’m going to try to get it in for an alignment this weekend, but it just seems like something else is the culprit here. Does anyone have any thoughts on what to check?

smokinAMD

Do you have any vibration in the steering wheel under braking?

S197steve

Not that I've noticed, but it does pull to the left when applying moderate to hard pressure on the brakes...

smokinAMD

It ALMOST sounds like one of the rotors isn't true. It happens sometimes, where I work part time (parts store) we had a batch of rotors ship to us that weren't completely true, and they all had to be machined before they could be used.

Another thing to check would be the hub. Pull the rotor off and clean the mating surface to the rotor up with a wire wheel.

S197steve

If one of the rotors wasn't true, then wouldn't it rub on the brake pad? I'm not ruling it out as an option, but it seems to me that I'd feel / hear the pad rubbing on the rotor. Also, the pads aren't really 'hot' after driving around for a while, I figure if there was some rubbing that particular pad would get hot.

smokinAMD

Not necessarily. It could be out of whack ever so slightly that it wouldn't touch the pad, but still be enough to cause the car pull a little.

The way that I'd go about attacking this would first be pull off both rotors, make sure the hubs are cleaned up nice and good and are smooth, same with the back of the rotor hats. Then get the tires balanced and have the allignment checked. If that doesn't solve it, then I'd go and take the rotors to a machine shop that can check the trueness of them under rotation. I wouldn't be surprised if one of them is ever so slightly out of whack.

Also need to make sure the lugnuts are torqued down good as well, but I'd suspect you already checked that.

Good luck.

Argonaut

Does this problem happen when you step on the brakes or when you are just driving down the road? If its the later, chances are its an alignment issue. Especially since you've stated there is no vibration. Perhaps you knocked something on the suspension when doing the brake changes or perhaps you've hit something (curb, pothole). Get it in for an alignment, then see if you still have the problem.

Norm Peterson

Was there visible tire wear (particularly with respect to evenness of that wear across the tread on all four tires) and what was your rotation pattern?

I've had very good experience with the ATE rotors, have them on two cars. HPS pads on three . . .

Don't be surprised that the grip level of dedicated summer performance tires gets kind of sucky when it's cold out. My GY Asymmetrics don't like the cold either, and wheelspin or sudden tailhappiness comes all too easily.

Norm

S197steve

Thanks for the feedback guys, once this cold snap works it's way through (it's in the 20s here today!!!) then I'll get out and start checking these things out.

Argo, the steering is very twitchy all the time, not just under braking. Actually, under braking it feels pretty stable, but just pulls to the left a little when I brake hard.

Norm, there really didn't appear to be any uneven wear at all. The tires have around 12k miles on them. Since they are directional, I can only rotate them front to back, not diagonally front and back.