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Warping Rotors a recurring problem...??


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I really love our 98 legacy Outback. One of the recurring problems seems to be warped rotors. The car has 120k miles on it. The last time the rotors warped, I replaced the rotors with slotted rotors (Power Slot), put in ceramic pads (Akibono) and braided steel lines all the way around (The brake lines were to improve the pedal feel). About 20k miles later, the rotors appear to be warped again.

 

I'm getting ready to go out and get a dial indicator to put on the rotors to see how much runout I have on the rotors. I will check to see if there is a problem with excessive runout on all the rotors. This should tell me if it is related to a specifc component (sticky caliper) or a general overheating problem.

 

Couple of questions:

1. Is this a problem common to Outbacks in this era (doesn't appear so by searching through forum archives).

 

2. Any thoughts or suggestions (I'm thinking aftermarket calipers)?

 

Thanks in advance)

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rotors don't usually "warp" per se. What tends to happen is pad material will be deposited unevenly from overheating the brakes. However, I would think that was much less likely to occur with better pads you're using. Here's what stoptech has to say about it.. I tend to agree, and they have some other very informative articles on brakes.

 

If the above isn't the case, the rotor could get a bit warped if the lugs were tightened improperly, or it could be caused by improper pad bed-in.

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Iam not taking about driving in the rain, I was speaking of crossing a river stream or other body of water, when the brakes are really hot. Where you live you may not have these conditions but where I drive there are a lot of places where the river or branches cross the road. Notice I said I have heard this I dont know how much truth there is in it.

"and be careful driving through water with them hot."

You're kidding me right? I can just see me serpentining down the road avoiding puddles...

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Sounds like you did a fine job replacing the rotors and brake lines- the ceramic brake pads is where you may have made your mistake. Some say ceramic pads last a longtime, which they do, but they do tend to heat up, which may be warping your rotors. Also, how are you braking? This may cause your rotors to warp at an unusually high rate.

Good luck.

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All,

 

Thanks for the comments and suggestions.

 

I was very careful to follow the procedure for bedding in the brakes when I first put them in. I cannot remember whether they were provided by the rotor or pad manufacturer. I think it was the rotor manufacturer.

 

On the issue of how agressively the brakes are applied, my wife drives the car. She doesn't race the car or drive very fast so I'm thinking that that is probably not the issue (I could be wrong of course). I know she doesn't ride the brakes either.

 

On the ceramic pads issue, are you sure the ceramic pads generate more heat? In my recollection, I thought they generated less heat. I'll do some research but let me know if you see information about this.

 

Adrian

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Didn't intend to be "e-thuggin" (having the nerve to say something hiding behind a screen). The premise of the water + hot rotor = warp has always seemed dubious to me. Considering this possibility in metalurgy, it would seem a too serious pitfall for any and all rotors if this were the case. Understood, you are not submerging or quenching the rotor with puddles as compared to crossing a stream but still you would expect a similar and cumulative effect might take place. I take interest in your thread because currently I too am suffering from warped rotors and certainly am open to all discussion.

Iam not taking about driving in the rain, I was speaking of crossing a river stream or other body of water, when the brakes are really hot. Where you live you may not have these conditions but where I drive there are a lot of places where the river or branches cross the road. Notice I said I have heard this I dont know how much truth there is in it.
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I really love our 98 legacy Outback. One of the recurring problems seems to be warped rotors. The car has 120k miles on it. The last time the rotors warped, I replaced the rotors with slotted rotors (Power Slot), put in ceramic pads (Akibono) and braided steel lines all the way around (The brake lines were to improve the pedal feel). About 20k miles later, the rotors appear to be warped again.

 

I'm getting ready to go out and get a dial indicator to put on the rotors to see how much runout I have on the rotors. I will check to see if there is a problem with excessive runout on all the rotors. This should tell me if it is related to a specifc component (sticky caliper) or a general overheating problem.

 

Couple of questions:

1. Is this a problem common to Outbacks in this era (doesn't appear so by searching through forum archives).

 

2. Any thoughts or suggestions (I'm thinking aftermarket calipers)?

 

Thanks in advance)

 

Are your rear brakes working? This will cause the front brakes to warp. Make sure the rear calpipers are not frozen.

 

nipper

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E- thuggin never heard that before, maybe Iam to far South. The only thing I know for sure about wrapping rotors is they dont go long after turning them before they wrap. I just break down and buy new ones instead of turning. Of couse mine get much hotter than most using it for postal del.

Didn't intend to be "e-thuggin" (having the nerve to say something hiding behind a screen). The premise of the water + hot rotor = warp has always seemed dubious to me. Considering this possibility in metalurgy, it would seem a too serious pitfall for any and all rotors if this were the case. Understood, you are not submerging or quenching the rotor with puddles as compared to crossing a stream but still you would expect a similar and cumulative effect might take place. I take interest in your thread because currently I too am suffering from warped rotors and certainly am open to all discussion.
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He is in Riverside and we don't have as many rust problems as you easterners. Before I gave up on it I'd try another type of pad after cleaning the rotor the best I could. I'm currently using Ozzie pads on both cars (Axxis) deluxe and pretty happy with them. Heck there isn't much to lose in time or money by tryin new pads.

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E- thuggin never heard that before, maybe Iam to far South. The only thing I know for sure about wrapping rotors is they dont go long after turning them before they wrap. I just break down and buy new ones instead of turning. Of couse mine get much hotter than most using it for postal del.

 

 

That is correct. If they're shuddering, you most likely have hard spots in the rotors. Turning rotors won't get rid of them, so once it wears a bit the vibration comes back.

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I do have one or two suggestions: Fit some Mintex pads. I have had good experience with these, and no amount of heat will cause pad deposits on the discs - aka "warping".

 

Next up: Do these vehicles have automatic transmissions?

 

If so, try bumping the gearstick into "N" when you intend to stand still - like traffic lights - and pulling the handbrake if you're on an incline.

The stick moves freely from "N" to "D" without any need for pressing the lock button.

This way you don't press the front brake pads onto the discs during stops.

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While we're on the subject.

 

Our '95 Legacy had a constant problem with warping rotors, and finally I had to replace them after selling the car to a friend. Our '00 Leg is starting to show first signs of warped rotors, so it is only a matter of time. I hate to have them turned, because I suspect (based on past experience with the '95) the 'fix' won't last long.

 

Are the Outback rotors thicker, if so will they fit in the legacy calipers, or can you all recommend an aftermarket that will hold up longer?

 

Not complaining, mind you, the '00 has well over 170,000 miles.

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hmm... probably. You could try re-bedding the pads or sanding the rotors. Although if they're 170,000 mile rotors, they might just be a little too thin by now.

 

The Outback and WRX have bigger but not thicker front rotors, so by getting WRX brackets and rotors you can have bigger brakes, although the 00-04 Legacy has decent brakes already. A lot of other Subaru owners (like me) take the rear brakes because they're the biggest discs short of STi brembos (06 WRX and LGT are the same diameter but vented). You can find front WRX brackets for less than $100, and the rotors aren't much more expensive.

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  • 1 year later...

2000 outback. I have been putting new rotors on it for the entire year I have had it. they only last a few thousand miles. then wobble! I replaced on caliper for sticking piston. but my rotors are def doing something. you can see the difference around the rotor. looks like hot spots. at least Napa warranties the rotors!

I haven't tried the sanding of the rotors. so that might be next.

but I also have a huge problem keeping the tires in balance! bought them new, get them rotated every 5 or 6 k.

no idea.

any suggestions out there.

ps, if anyone read my HG posts, I did a road trip ohio to georgia last w/e. no probs

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Are you properly bedding in the pads on the new rotors? Sanding is not recommended, at least not by stoptech: "Do not use regular sand paper or emery cloth as the aluminum oxide abrasive material will permeate the cast iron surface and make the condition worse. Do not bead blast or sand blast the discs for the same reason."

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97 Legacy L, disks all four corners, all working, all warped 5k miles after being replaced. It's just part of the package.

 

Of course, with the shuddering clutch, wind noise leaking past the door and window seals, road noise coming through the floor, and motor ticking I barely notice :grin:

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2000 outback. I have been putting new rotors on it for the entire year I have had it. they only last a few thousand miles. then wobble! I replaced on caliper for sticking piston. but my rotors are def doing something. you can see the difference around the rotor. looks like hot spots. at least Napa warranties the rotors!

I haven't tried the sanding of the rotors. so that might be next.

but I also have a huge problem keeping the tires in balance! bought them new, get them rotated every 5 or 6 k.

no idea.

any suggestions out there.

ps, if anyone read my HG posts, I did a road trip ohio to georgia last w/e. no probs

might want to get better pads and/or upgrade to wrx sized front rotors by getting new brackets.

 

Having a better pad that is suited to higher temps means it won't overheat and leave uneven deposits on the rotor as easily.

 

Some examples: Hawk HPS, EBC redstuff and yellowstuff, axxis ultimate, carbotech bobcat

 

Also make sure the lug nuts are tightened properly with a torque wrench. Otherwise the wheel will squeeze the rotor unevenly and it will warp.

 

97 Legacy L, disks all four corners, all working, all warped 5k miles after being replaced. It's just part of the package.

No, it's not. I have the same tiny brakes on my car and take it road rallying and up on fun roads in malibu. No TV or vibration with very hard use, including one time when I had smoke coming out of the wheels. I use a torque wrench when tightening my lugs and don't sit there stopped with my foot on the pedal when the brakes are hot.

 

 

My last set of pads were hawk hps, which I couldn't get too hot on public roads. My current raybestos ceramics are crap compared to them. Next up I'm trying Axxis Ultimates with bigger brakes all around.

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While we're on the subject.

 

Our '95 Legacy had a constant problem with warping rotors, and finally I had to replace them after selling the car to a friend. Our '00 Leg is starting to show first signs of warped rotors, so it is only a matter of time. I hate to have them turned, because I suspect (based on past experience with the '95) the 'fix' won't last long.

 

Are the Outback rotors thicker, if so will they fit in the legacy calipers, or can you all recommend an aftermarket that will hold up longer?

 

Not complaining, mind you, the '00 has well over 170,000 miles.

 

I have the same problem on my 03 OBW and am also interested in this thread. My warping problem got pretty bad so I finally decided to replace the fronts with brembo blanks and axxis XBGs. I decided to try to XBGs because i had the ultimates on my honda and they performed very well but were a little too dusty. I also made sure that I bedded the pads and rotors according to the manufacturers recommendations. Anyway, the replacement seems to work because I haven't had any major shimmying issues for awhile.

 

When I asked the question back a couple years ago, I was told that if installed and torqued correctly, rotors should not warp. One suggestion was to do the bedding process every now and then. Bring the car to about 40-50mi and then brake suddenly until it almosts comes to a complete stop but don't let it stop.(Do this in a safe place) Let the car roll and the do this again. Repeat this about 6 - 8 times and it should remove most of the deposits on the rotors. I tried it it seemed to work quite well so I've been doing it whenever I feel a slight shimmy when braking. Also, something else that was pointed out is not to stand on the brakes at an intersection especially when they're hot because it makes the pad material stick to the rotor.

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When I asked the question back a couple years ago, I was told that if installed and torqued correctly, rotors should not warp. One suggestion was to do the bedding process every now and then. Bring the car to about 40-50mi and then brake suddenly until it almosts comes to a complete stop but don't let it stop.(Do this in a safe place) Let the car roll and the do this again. Repeat this about 6 - 8 times and it should remove most of the deposits on the rotors. .

 

I do that in downstate NY and ill either get run over by car or taken in by the cops :(

 

nipper

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