Bad rotors
- Thread starter Logan56860
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David Young
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Rotate your tires (wheels). If it still vibrates, then you'll know you have a warped rotor.
redNfast
Active Member
Sounds like it, rotors warped usually most noticeable at lower speeds, coming to a stop. Where they changed or turned recently?
Auto zombie types, after market rotors will wrap (run out) in a very short time. As will rotors turned, best practice. changeing rotors, OEM for street.
Does it cost more absolutely, do they last much longer absolutely, as well as the pads.
Auto zombie types, after market rotors will wrap (run out) in a very short time. As will rotors turned, best practice. changeing rotors, OEM for street.
Does it cost more absolutely, do they last much longer absolutely, as well as the pads.
All tires have been recently balanced. I figured it was rotors, just thought I would throw it out there before I put on new ones. Easier, and faster to just put on new ones these days.
Of all my cars in my life, I only get warped rotors with automatic tranny. Has to be due to sitting after a stop with your foot on the brake with an auto and the pads trapping all that heat. Stick, you can let your foot off the brake at the stop. Not sure if it is true, but makes sense to me.
Thanks for the reply
Of all my cars in my life, I only get warped rotors with automatic tranny. Has to be due to sitting after a stop with your foot on the brake with an auto and the pads trapping all that heat. Stick, you can let your foot off the brake at the stop. Not sure if it is true, but makes sense to me.
Thanks for the reply
- Mar 7, 2002
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I'm the other way. I prefer sending my customer out the door with machined OEM rotors rather than aftermarket new. New OEM is best, but when cost is a concern, I'll take machined OEM all damned day over the Chinese
from a parts store. (Of course, I have a ProCut on-car lathe at work, I can get them perfect every time.)There's a lot of misinformation in this thread. I'm going to tackle some of that.
The majority of the time, the rotor itself isn't warped (there are times when they are, I'll get to that in a second). What is usually happening is a buildup of brake pad material on the rotors causing the pulsation. If you feel the pulsation in the steering wheel, it's usually the front rotors, if you feel it coming up through the seat, it's usually the rears. Machining the rotors removes the buildup and provides a uniform surface for the pads to grip. The problem is more prevalent than ever with modern semi-metallic, non-asbestos organic, and ceramic pads (the old asbestos-based pads were nowhere near as bad about it, but they had their own issues). A correctly machined rotor (cut as few passes as possible, cut evenly on both sides without cutting overly deep, with the machine setup properly so it doesn't chatter or squeal, and not cutting the rotor below minimum thickness spec) will perform as well as a new rotor for nearly as long. The second most common cause is rust buildup on cars driven through the snow in the salt belt. This is especially a problem on non-vented rear rotors on Nissans for some reason.
As far as when a rotor is actually warped, that happens a few different ways:
1. Some idiot really overtorques the lug nuts or wheel bolts, causing the rotor to deflect. Throw a few heat cycles on that and the problem is permanent, and machining won't fix it because the rotor will be imbalanced even after machining.
2. The rotors get cooled too quickly after being heated up from heavy stop-and-go traffic or a long deceleration off a highway. This happens a lot when someone goes straight to a car wash or drives through a puddle immediately after getting the rotors good and hot. This usually only warps the rotor slightly and at the surface layer, machining can fix this.
3. The brakes are abused, causing the rotors to overheat. If your rotors are blue, you're beating on them too hard. Machining may help, but rotors that have been heat-cycled to that extent are prone to having "hard spots" in the metal beneath the surface, meaning the problem will return.
For my shop alone. This is why I prefer new rotors. We use Wagner products.
@74stang2togo If I had a ProCut at this shop I would be turning these all day long and on the car to boot I think my mechanic would try and kiss me. BUT I have this lathe that is older than I am. This thing will take 30 minutes a rotor and is a demon to find parts for.
@74stang2togo If I had a ProCut at this shop I would be turning these all day long and on the car to boot I think my mechanic would try and kiss me. BUT I have this lathe that is older than I am. This thing will take 30 minutes a rotor and is a demon to find parts for.
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redNfast
Active Member
Wagner........... good stuff ^For my shop alone. This is why I prefer new rotors. We use Wagner products.
- Mar 7, 2002
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I hate the old slow single speed lathes. Hunter 10 speed or a ProCut on-car or nothing. Can't make money cutting rotors (at the technician level, anyway) with a machine that slow.For my shop alone. This is why I prefer new rotors. We use Wagner products.
@74stang2togo If I had a ProCut at this shop I would be turning these all day long and on the car to boot I think my mechanic would try and kiss me. BUT I have this lathe that is older than I am. This thing will take 30 minutes a rotor and is a demon to find parts for.
Wagner's brake parts are about as good as anyone else's off the boat from China.
All good points.
This car has 50K miles, I've had it for 2K, and it has always been a FL car. That answers some variables.
I'll assume the previous owner was a moron and go from there. A good set of rotors and brakes are cheap enough and easy enough.
Now the tough one, I want vented black rotors, front and back. Non Brembo, standard 2013 GT. Low miles, mostly easy braking. and?????????
This car has 50K miles, I've had it for 2K, and it has always been a FL car. That answers some variables.
I'll assume the previous owner was a moron and go from there. A good set of rotors and brakes are cheap enough and easy enough.
Now the tough one, I want vented black rotors, front and back. Non Brembo, standard 2013 GT. Low miles, mostly easy braking. and?????????