I did have to have new bearings in one of the front wheels a couple of years back. Maybe the other front wheel has suffered the same fate.

I'm bringing a list to him of these things to check - thanks to all.

I do trust him as a mechanic. The last time he did replace the bushings, so he is indeed looking for the problem not just replacing the rotors over and over. He doesn't know yet that the problem has returned.

 

I'm gonna take a second Guess!!
The rotors, the quality MAY have recently dropped...lets face it, cost cutting is common, and now that r53 are out of warranty, the OEM/aftermarket parts may have changed....
What I would do is change brands of rotors/pads.....see what happens.
That and make sure the rims are HAND torqued!!
Good luck!!

 

Have you asked your mechanic if he's actually dial-indicated the warped rotors? If so, what's the run-out? Have you replaced your control arm bushings, ball joints and/or tie rods? With that high mileage, you're well overdue. What I'm getting at is perhaps you're replacing the wrong components. Ask yourself: When I step on the brakes, is the brake pedal pulsating or is the steering wheel?

 

I don't know if he's done that yet.

He replaced the tie rods and bushings. Not sure about the ball joints.

I feel it much more in the steering wheel than in the pedal.

 

Thanks for the feed-back. Suggest you get specific figures for run-out. The rotors should have no more than +/-.002"or .004" total run-out. If they're in spec., then I'd look closely at front suspension componentrs, especially the ball joints.

 

Warped rotor????? Read the white paper written by Caroll Smith, a well respected engineer and race car fabricator:

http://www.stoptech.com/technical-su...nd-other-myths

I would expect that since the problem goes away for a while after installing new rotors, it is caused by uneven pad material build-up on the surface. The stock MC pads behave like they have high carbon and iron content; lots of aggressive black dust

Are the new rotors Blanchard ground and do they come with a preservative oil on them? If so, they must be thoroughly cleaned off. White rag and lacquer thinner, mineral spirits, brake cleaner, etc. If the rag shows any gray metal, new rag and more solvent until nothing shows.

Certain types of pad materials are more prone to taking the microscopic bits of metal from the gin ding process and piling it up in spots on the rotor surface. Once you have a high spot, it will generate more heat under braking at that location, and weld/bond more metallic rotor or brake pad bits to that same spot. Sometimes you can easily see the pad material and scrape it off with the end of a flat file.

I would switch to a ceramic brake pad. They are fine for street driving, don't dust as much as the OEM pad and the dust is white/gray instead of black.

Carbotech makes some great ceramic pads, but are more expensive than some.

 

Resurrecting an old, but relevant thread that describes my problem perfectly.
Wondering what the solution was?

 

The OP hasn't posted on this site in over a year so he is probably not around anymore to answer..

 

You could try sending him a PM asking him to post in the thread. That should send him an email if he didn't turn that option off.

 

I'm here! I'm here!

Apologies for not coming back and posting the solution. My mechanic eventually theorized that one side of each caliper was not fully releasing so it dragged the pad against the rotor and warped it. It had been many many miles since my last complete brake job, so that's what he suggested (new fluid, new calipers, new pads).

Haven't had the problem since.

 

Thanks for following up!
Just got my car back from the shop. New rotors, and they cleaned off the sticky anti-seize compound from the guide pins. Used a high temperature silicone lubricant more appropriate for the job. Now we'll see what happens. Based on your experience, hoping nothing more than normal, shudder free braking!

 

Both my front rotors have pad imprints and exhibit the shaking/pulsing when braking. I recently tried a new brand of rotor and pad. Like ZippyNH said, rotor and pad quality varies. I believe this is my problem. Either the rotors are not dissipating the heat efficiently or it's the pads. For now it's bearable, but I will be switching to another brand of rotor/pad next time.

 

Eddie has one reason. If you brake hard to a stop the rotor cools, but the part under the pad stays hot and can and will warp rotors. When I stop hard I let the car roll slightly to avoid that.

 

i too am experiencing this shaking and shuddering in both steering wheel and via the pedal. i too have "new" pads / rotors (ECS slotted or something, theres a thread about how these may or may not be junk due to ease of "warping"), and EBC red stuff.

they were fine for a while, then the shuddering started.

i do have 111k on the car, and i know the LCA bushings are nearly shot; ill be taking the car to mini soon for an oil change and will be asking them to check the brakes for the shuddering. hoping its "just" those tie rod ends and LCA bushings (as i have new ones and polys for the LCAs)... jut not looking foward to the $600 repair bill to put these new bushings in.

will report back when mini does my analysis!