Warped rotors causing pull to right?
 

I just installed new shocks all around on my 69S and set the ride height as well. Before I did this, the car had a distinct pull to the right and that pull is still there. Nothing seems to get rid of it. I have been working with the 911 alignment handbook posted on this BBS and one of the suggestions in that pamphlett is that a warped rotor can cause the car to pull even when not braking. So I checked the front rotors and even without the brakes applied there is a definite spot on the right rotor where it rubs the pads. I can see a very slight warping, but really nothing significant. Is this enough to cause the car to pull? Any other suggestions? The car is scheduled to be aligned and corner balance in a few weeks, but I would like to get it set up as good as I can before then.

Thanks.

Check your brake lines. Old soft rubber lines can cause uneven braking.

Thanks Jamie - the pull is not during braking but during regular driving -

Warped rotors will not cause a car to pull. The most you will notice is a pulsation in the pedal.

You either have an alignment issue (still) or a bad tire.

Have you tried swapping tires on the front to see if there is a difference? Are your tires feathered or cupped? Even if the alignment and corner balance is accurate a tire can cause a pull.

Even new tires can cause a car to pull to one side or another if there is a bad belt or an odd tread pattern that does not agree with the car.

-Jeff

oops - Looks like I didn't read your post closely enough...

According to the 911 alignment handbook I have if the rotor is rubbing on one side during driving it will cause the car to pull to that side - makes sense to me?? The tires and wheels are brand new, the tie rods and ball joints are near new, and I believe the car is pretty close on the corner balance. I am going to replace the rotors, but perhaps it will not make a difference.

I would try swapping tires as a cheap check first.

Thanks Chris - the tires are brand new and it did this even before I put them on (the old tires were brand new as well). I want to change the rotors out anyway so no big deal there.

I think you are misunderstanding the handbook...

If it is anything related to brakes it is that you have a caliper dragging not the fact the rotor is warped. The two actually go hand in hand as in if you have a sticking caliper or it is dragging (meaning that the caliper is applying braking force on it's own on that wheel and you are not at the pedal) that will warp a rotor.

So the rotor may be warped but that in itself is not causing the pull. I would check your front calipers, slides, seals pads etc.

Are you doing this alignment/corner balance yourself?

-Jeff

same exact thing a couple months ago, i posted a picture as well. A rebuild on the calipers fixed the whole thing
http://forums.pelicanparts.com/porsche-911-technical-forum/199409-new-rotors-uneven-wear-pattern.html

Have you checked cornor weights? and Alignment?

guys, i'm really sorry to hijack this thread, but I have a question I think only zcat3 can answer... zcat if you can check your PMs I'd appreciate it, I sent you a link to a thread on the 911 board.

Thanks

jbrinkley's post above sounds convincing. But, you say you adjusted your ride height recently? I monkeyed with my ride heights and spent the next 3mos with the same problem. My car's pull to the right wouldn't go away even after 2 alignments with near perfect specs. Finally, I was convinced by a member on this board that my corners were out of balance.

My home remedy to check the theory: I raised the front right ride height a bit to "throw" some weight left/aft and it was remedied - straight as an arrow.

If it's not the brakes, you'll definitely be good once you can get it in for that cb and alignment...

A hanging piston in a caliper due to a bore issue or a swollen line will cause a pull as will an alignment issue....

Do you have a pyrometer? Drive the vehicle for ten minutes and shoot the temp of the front two rotors. If one is signifcantly higher in temperature you have a hanging piston...R&R the brake system.

When was the last time the brake system has been inspected and serviced with fresh brake fluid?