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Warped rotors?

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Okay, so I have am invariable whisping/rubbing noise coming from my rear passenger's side wheel. I thought it was a stuck caliper, but when it comes to brakes Im a novice. So I had my buddy look at it, the caliper had some gunk in it, but we cleaned it and greased the pistons up a bit. No change. He seemed to think it could be that rotor is warped and is rubbing, but I wanted to get some opinions here before I order a replacement one.

 

And Im at 94,000 miles on the clock. Normal ware I would assume.

Okay, so I have am invariable whisping/rubbing noise coming from my rear passenger's side wheel.[...]the caliper had some gunk in it, but we cleaned it and greased the pistons up a bit.[...]

Caliper mechanisms should be free to slide, but greasing the pistons :confused: :-\ :eek: ?!

 

The noise would concern me somewhat, but even more so, where, exactly, did you lubricate, and with what?

Dragging dust shield? Wheel bearings? I've got 158k on the clock and my rotors aren't warped (and they're the stock ones too).

  • Author

The noise would concern me somewhat, but even more so, where, exactly, did you lubricate, and with what?

 

Well I took the caliper apart and fired some WD-40 into each of the Piston holes.

 

Dragging dust shield? Wheel bearings? I've got 158k on the clock and my rotors aren't warped (and they're the stock ones too).

Yeah, but if you have an L, thats a 2.2L vs. my 2.5L, different speeds & weights, different braking needs and I go to Penn State so I drive up and down many a mountain to get back and forth, which could cause warping.

Well I took the caliper apart and fired some WD-40 into each of the Piston holes.[...]

Petroleum products should never be used on brake hydraulic components (parts that come into contact with the brake fluid); they can swell, distort, or deteriorate seals, etc. Even if it wasn't needed before, I'd now suggest rebuilding the caliper. Usually only brake fluid itself is used for "lubrication" of brake hydraulics. The caliper has to be free to slide, and the pads also need to move, so other lubricants (usually silicone-based) specifically designed for brake applications should be used as required. If there's any chance that the WD-40 got into the flex line, that could have been contaminated/damaged as well, and you should consider replacing it. Flush the hard line before remounting things, and of course bleed as needed afterward.

  • Author
Petroleum products should never be used on brake hydraulic components (parts that come into contact with the brake fluid); they can swell, distort, or deteriorate seals, etc. Even if it wasn't needed before, I'd now suggest rebuilding the caliper. Usually only brake fluid itself is used for "lubrication" of brake hydraulics. The caliper has to be free to slide, and the pads also need to move, so other lubricants (usually silicone-based) specifically designed for brake applications should be used as required. If there's any chance that the WD-40 got into the flex line, that could have been contaminated/damaged as well, and you should consider replacing it. Flush the hard line before remounting things, and of course bleed as needed afterward.

 

Really? Ive never heard that before.

Okay, so I have am invariable whisping/rubbing noise coming from my rear passenger's side wheel. I thought it was a stuck caliper, but when it comes to brakes Im a novice. So I had my buddy look at it, the caliper had some gunk in it, but we cleaned it and greased the pistons up a bit. No change. He seemed to think it could be that rotor is warped and is rubbing, but I wanted to get some opinions here before I order a replacement one.

 

And Im at 94,000 miles on the clock. Normal ware I would assume.

 

If you got 94k miles from one set of rotors you are way ahead.

 

It is my opinion that 90% of all "warped" rotor problems are caused by uneven pad deposition on the rotor surface.

 

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

 

Of course, resurfacing or replacement corrects both conditions. It's still the rotor.

If you got 94k miles from one set of rotors you are way ahead.

 

It is my opinion that 90% of all "warped" rotor problems are caused by uneven pad deposition on the rotor surface.

 

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

 

Of course, resurfacing or replacement corrects both conditions. It's still the rotor.

 

and the other 10% is the mfg specing out too thin a rotor to start off with.

 

nipper

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