Brake Rotors

[Bill Zeller]

I have a Legacy 2.5 GT with 70k miles on the clock and I'm on my 3rd set of rotors. The rotors seem begin to warp after 5k miles and really cause the steering wheel to shake by 10k. The diagnosis is consistent from the dealer and the two independent shops I have used. The fix is resurfacing the rotors until they have to be replaced.

 

I don't drive it any harder than any other car I have and they do not seem to have this problem.

 

Anyone else have this problem? Any solutions, solutions?

 

Bill

[mwiener2]

The diagnosis is wrong.

 

Get a set of new rotors and aftermarket brake pads.

 

You drag your brakes too much. Try to use a heavier foot on the brake pedal.

[shadowsports]

+1 on wrong diagnosis. Our rotors don't warp. Sounds like build up. Lots of good aftermarket alternatives. Hawk pads, Stoptech, DBA, Brembo or ATE all make good rotors for our vehicles.

[joeblow]

A few of the vendors have a full brake kit (rotors, performance pads, and brake lines) for like $550-$700 depending on the performance level you're looking for. That is probably comparable to what the dealership will charge just to resurface the rotors.

 

So find a friend that can help out and do a brake swap yourself. Its very easy, but helps to have a second set of hands.

[Max Capacity]

When your rotors begin to warp all you need to do in most cases is rebed the brakes.

 

It's been covered a number of times.

 

Do 3-4 almost stops and fast as you can from 55mph, do not stop between each time. Don't lock up the brakes, just almost lock them. You need to be that hard on them.

 

Then drive from 1 mile without stopping to let them cool.

[rnstein69]

When your rotors begin to warp all you need to do in most cases is rebed the brakes.

 

It's been covered a number of times.

 

Do 3-4 almost stops and fast as you can from 55mph, do not stop between each time. Don't lock up the brakes, just almost lock them. You need to be that hard on them.

 

Then drive from 1 mile without stopping to let them cool.

 

This.

 

I had a similar issue and rebed my brakes and my problem is resolved. You have to keep slowing down from 55 or 60 to 10 pretty hard, almost to the point of triggering abs. When you just start to experience brake fade, drive the car on the highway for 20 minutes or so without stopping so that the brakes can cool.

 

Check out these threads:

 

http://legacygt.com/forums/showthread.php/proved-myself-rotors-do-not-warp-140571.html

 

http://legacygt.com/forums/showthread.php/video-article-swap-between-street-and-race-pads-139306.html?t=139306

 

http://legacygt.com/forums/showthread.php/video-bed-brake-pads-and-rotors-126622.html?t=126622

 

http://www.stoptech.com/tech_info/wp_bedintheory.shtml

[notthesnail]

Rotor warping, for all practical purposes, is a myth. What you are feeling is a build-up of pad deposits on the rotor. This happens when the rotors are hot and the pads are kept in contact while stopped. Looking at the rotor you can probably see pad-shaped images around the wear area. Resufacing will fix this. So will re-bedding and it has the advantage of being free and requiring almost none of your time. Neither will correct the source of the problem.

 

If your rotors have already been resurfaced and are close to end of life, then rebed until you have the parts you need to do a full brake job.

 

If your rotors are new or close to it, then rebed to clean them up, swap in some better pads, and bed them in according to the manufacturer instructions (which is usually a series of near stops from progressively faster speeds, followed by a cooling down period).

 

As for pads, StopTechs are nice, but I find them dusty. For regular driving, I'd probably go with Hawk HPS or Ceramics. If you're changing rotors, get blanks. No slots, no holes; they're overrated (and overpriced). I'm going DBA 4000 next time, but there are other good brands available.

[JoeFromPA]

I'll add that the OEM pads seem much more prone to leaving deposits. Most sets of aftermarket brake pads will not leave those deposits....

 

I'm at 46k miles on my 08 LGT. Had Subaru machine the fronts once, for free, because they noticed a vibration and wanted to give me a freebie. Stock rotors are fine and my new pads haven't left deposits since.

[Brock Samson]

Rotor warping, for all practical purposes, is a myth. What you are feeling is a build-up of pad deposits on the rotor. This happens when the rotors are hot and the pads are kept in contact while stopped. Looking at the rotor you can probably see pad-shaped images around the wear area. Resufacing will fix this. So will re-bedding and it has the advantage of being free and requiring almost none of your time. Neither will correct the source of the problem.

 

If your rotors have already been resurfaced and are close to end of life, then rebed until you have the parts you need to do a full brake job.

 

If your rotors are new or close to it, then rebed to clean them up, swap in some better pads, and bed them in according to the manufacturer instructions (which is usually a series of near stops from progressively faster speeds, followed by a cooling down period).

 

As for pads, StopTechs are nice, but I find them dusty. For regular driving, I'd probably go with Hawk HPS or Ceramics. If you're changing rotors, get blanks. No slots, no holes; they're overrated (and overpriced). I'm going DBA 4000 next time, but there are other good brands available.

 

[mwiener2]

If you're changing rotors, get blanks. No slots, no holes; they're overrated (and overpriced).

 

holes are silly, but slots are actually functional and useful

[coldmm803]

First off, welcome to the forum. Lots of useful info around here.

 

As the others have said. It's not the rotors that are the issue it is the pads. I experienced this from the start when I got my 09 LGT in November with 100 miles on it. In January I had the dealer turn down/resurface the front rotors and put on Hawk HPS pads on all 4 corners and have not had the issue since.

[HarryN]

holes are silly, but slots are actually functional and useful

 

In my racing days, I avoided drilled rotors like the plague. They had the tendency to crack overnight. But then again, this is under harsh driving conditions and not daily driving.

[LosAngelesLGT]

^I thought cross drilled rotors were to reduce the unsprung weight when racing. After racing them, toss 'em out and replace right? (I mean for sponsored guys or really deep pockets, I can't afford to do it to save 6oz)

[HarryN]

Well yeah, the point of having the drilled rotors was to lower the unsprung weight. But changing out those rotors were super expensive. I surely was not sponsored or had deep pockets at the time.

[SATSFYD]

holes are silly, but slots are actually functional and useful

 

Hey I like "holes"... hehehe. But really the posts above are right; cross-drilled is a waste of money... (more less for show) slotted for rain ... a lot of rain and track duty.

[mwiener2]

Slotted rotors tend to have less problems with deposits and recover from glazing better as well.