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Warped Rotors -- 2002 Forester


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I bought my 2002 Forester brand new. It now has 31,000 miles on it. The rotors on the brakes have warped twice and been ground (or whatever). It's time to do it again. The service dept. is telling me it's my problem, that I must brake too hard. I've been driving for 37 years and have never had this problem before. It seems to start up again in the summer, when the weather's in the 100s and I've been on a long drive of start and stop driving. I do mostly flat driving -- no mountains. If I have to make a panic stop, it's guaranteed to warp the rotors again.

 

This is my first Subaru. Is this a common problem?

 

Of course the rotors are not a warranty item. Would I be out of place suggesting that they replace them under warranty anyway?

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Guest lothar34

How many times can the rotors be ground before they need to be replaced? I think I'd have mine replaced if they had already been ground twice.

 

Do you ever drive through water while they're hot?

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Well. . . after any emergency (or other hard condition) stop, it's best not to stay on the brake pedal. Right after that is when the pads are cooking, and keeping them in contact with the rotors WILL eventually warp them.

 

If you must brake hard, let-off the brakes if you can to let the pads and rotors cool before stopping completely. Or, if you're in an automatic, you can pull over and put it in "park" without setting the parking brake. The transmission will keep you from rolling anywhere, and you'll not be keeping the pads pressed against the rotors while everything's cooling-off.

 

If you have to replace your rotors, you may want to consider upgrading to a design that will cool-down faster than your OEM ones.

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they just recieve uneven deposits. The guy who did the brake work for Carrol Shelby on the Cobras, whose name escapes me at the moment, has written an interesting article on this. I have it at work if you are interested.

In the heat you run and the traffic conditions where you are you may be experienceing unusual problems. If it was my car I would install new rotors and experimant with pads of a different material.

My Forester had chattering brakes when I got it and I replaced my rotors and added Austrailian 4WD pads. The pads have a slot in them to increase cooling and I figure if they work in Aussie heat they will work for me.

So far no problems mate,and it has been about a year and 10,000 miles.

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How many times can the rotors be ground before they need to be replaced? I think I'd have mine replaced if they had already been ground twice.

 

Do you ever drive through water while they're hot?

I doubt that I've ever driven through water while the weather is extremely hot because it doesn't rain here in the summer. In the winter, I drive through water. I went back and checked the repair records; first time was in March, second time last November. Not summer months as I thought.

 

Yes, I'm concerned about having good brakes after the third grinding!

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they just recieve uneven deposits. The guy who did the brake work for Carrol Shelby on the Cobras, whose name escapes me at the moment, has written an interesting article on this. I have it at work if you are interested.

In the heat you run and the traffic conditions where you are you may be experienceing unusual problems. If it was my car I would install new rotors and experimant with pads of a different material.

My Forester had chattering brakes when I got it and I replaced my rotors and added Austrailian 4WD pads. The pads have a slot in them to increase cooling and I figure if they work in Aussie heat they will work for me.

So far no problems mate,and it has been about a year and 10,000 miles.

Uneven deposits is certainly a possibility. I live in the country and it's quite dusty. I can see rust on the brake cylinders (?). Thanks. I will pursure your suggestion with the Subaru dealer.

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Well. . . after any emergency (or other hard condition) stop, it's best not to stay on the brake pedal. Right after that is when the pads are cooking, and keeping them in contact with the rotors WILL eventually warp them.

 

If you must brake hard, let-off the brakes if you can to let the pads and rotors cool before stopping completely. Or, if you're in an automatic, you can pull over and put it in "park" without setting the parking brake. The transmission will keep you from rolling anywhere, and you'll not be keeping the pads pressed against the rotors while everything's cooling-off.

 

If you have to replace your rotors, you may want to consider upgrading to a design that will cool-down faster than your OEM ones.

Of course with this ongoing problem, I now try to avoid all hard stops, but sometimes it is unavoidable. That may be the problem, though. A hard stop in rush-hour traffic that you're stuck in. I also have ABS brakes, which I thought you were not supposed to pump, but keep them engaged. Frankly, I think I'd rather go buy a Toyota than pull over to park and let the brakes cool. This isn't a Model T! I'm not criticizing you....just think a car should be designed better. My Nissan, which I had for 11 years with 140,000 miles on it was driven in the same conditions and I never had this problem.

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Assuming the specification for the rotors on an '02 are the same as for an '03 the following are the rotor speficications:

 

Front Rotor: Standard thickness .94 inch Minimum thickness .87 inch

 

Rear Rotors: Standard thickness .39 inch Minimum thickness .335 inch

 

If you've already had these turned twice, you may be approaching the minimum.

 

Have you been replacing the pads after you have the rotors turned? I believe that is highly recommended. In addition, some after market pads, particularly those that claim less dust, can also generate more heat, which means, in my opinion, more trouble.

 

Bill

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  • 2 weeks later...

This is not a common problem with subarus to have rotors warp twice within 30k miles. I have a 99Legacy with stock brakes and no warp problems. But a forester is a heavy body on the Imprezia platform. I dont know if the brakes are bigger than imprezias to compensate for this?

 

I have several suggestions. Just my $.02

 

1. Downshift when slowing down and use the engine to slow the car this can work on manual and Auto. (DONT DROP IT INTO FIRST DOING 65, JUST DOWN ONE GEAR WHEN YOU REACH ABOUT 45) ALSO IN TOWN USE 3rd (AUTOMATIC) Gear.

 

2. Dont hold your foot on the brake the entire time you are stopping - gently pulse the brakes a few times as you stop.

 

3. Get NEW rotors and brake pads put on. THE OLD ONES MAY JUST BE BAD. (resurfacing or turning is a wast if you ask me GET NEW)

 

4. GO TO A DIFFERENT SHOP - Those guys are taking you to the bank. They can turn the rotors just enough to make it smooth but They DIDNT TURN THE ROTORS ENOUGH to prevent it from coming back. My rule is that MOST Rotors should only be able to take one good resurfacing to be safe. Even if its within tolerances can reduce the pedal pressure as the pads wear. Making you have to push the pedal further to engage the brakes. NOT GOOD IN EMERGENCY STOPPING SITUATIONS.

 

4.Make sure they lube the caliper sliders so they can move back and forth around the rotor. IF the caliper cant slide back and forth the pads can rub and heat the rotors- THUS warpage.

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Not many people are as hard on brakes as rural mail del. (Tx. heat) fully loaded car with nearly 500 stops a day, most from at least 50 miles an hour. If I turn my rotors one time they will wrap within a few days, (shaking when on brakes) Dont even turn them once go to Auto Zone and get their rotors they are cheap and they hold up for me on my job,so they will surely hold up to whatever kind of driving you are doing. When rotors are turned they are much smaller and wrap much easier.

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