Rusty brake discs

[Birdman]

Is this as common as I'm being lead to believe?
I've been getting a rough vibration running through the car during heavy braking. After road testing and a visual inspection the garage said it was down to rust patching on the rear brake discs. Most likely cause they said was washing the wheels and not moving the car for a day or more. I've never encountered this problem before and it seems unlikely I could trash a set of discs so easily. Besides, I don't wash my car.
Can't find any reference to patching on the forum and wondered if anyone else has had this experience.

 

[230K]

Hi

Most likely warped discs?

Other vexplanation seems very strange

230K

 

[jimmy]

Yes it is not unheard of.

My dad used to have a BMW M5 years ago, it only got used occasionally, maybe every other weekend. It used to get driven then put in the garage and left, the pads would quite often rust onto the discs so bad you had a real job to move it. He was forever taking it back to the dealer because of the same problem as yours. More often it was the rear discs, but the fronts also caused problems.

I must admit most braking vibrations are caused by the front brakes as they do much more work, this is usually felt as a wobble in the steering wheel when braking. I would have thought the rear brakes would make a noise rather than a vibration.

Likewise, never quench hot discs when washing the car, allow the brakes to cool before washing.

 

[Birdman]

Interesting it was the M5 model, mine being an E55. I wonder if it could be something to do with having thicker discs or using a harder wearing material. Apparently the problem is the pads sit against the wetted disc and keep them dry while the rest of the disc rusts, leaving a high spot. The patching starts a harsh vibration that is felt first through the driver's seat and eventually feeds through to the steering wheel at maximum braking effort. Course, it might all be b*ll*cks.
Never encountered the problem on other high performance cars I've had.

 

[Satch]

Does not take a lot of surface differences to induce brake vibration. The cast iron used in most brake rotors has had to change in recent years to a softer, more wear and rust prone material because of changes in the pads. Ah, progress.

My disks seem to rust up if you even show them the hosepipe.

"Warped Disks"? Read this then decide if they actually exist or not:

http://www.stoptech.com/whitepapers...rotors_myth.htm

All down to surface inclusions building up.

 

[DITTRICH]

I got this sort of problem with my C230K when I left it parked for a month whilst on holiday. It takes a little while to get rid of the rust build up. After a few days, all was back to normal, but meanwhile I could always 'feel' the discs were uneven cos a bit was sitting under the pad in one spot for a whole month.
Les

 

[jgevers]

The W210 seems to have a problem with rust and possible warping of rear discs. I find that most w210s in my garage have had the 'vibration problem' at some time in their life. For some unknown reason the larger engined ones seem to suffer more?

I have found that if the customer allows us strip and clean the rear brakes at every service the problem doesn't come back. Mind you, the rear discs aren't as expensive as you might think.

regards,

Job

 

[Birdman]

The W210 seems to have a problem with rust and possible warping of rear discs. I find that most w210s in my garage have had the 'vibration problem' at some time in their life. For some unknown reason the larger engined ones seem to suffer more?

I have found that if the customer allows us strip and clean the rear brakes at every service the problem doesn't come back. Mind you, the rear discs aren't as expensive as you might think.

regards,

Job

That checks out!
Any idea what I should pay for a set of rear discs for the E55 W210?

 

[GordonTarling]

That checks out!
Any idea what I should pay for a set of rear discs for the E55 W210?

Just paid around £27 each for the rear discs on my W210 E320CDI - changing them due to vibration.

 

[Birdman]

Just paid around £27 each for the rear discs on my W210 E320CDI - changing them due to vibration.

Extraordinary! I'm being told a pair of front discs and pads is around £500 fitted, AMG parts can't be so very different as they are after all made by the same factory.
An update on my vibration experience. I washed the car, for the third time in as many years, took it out for some heavy braking in order to prevent the accursed 'rust' patching and found the problem had cleared itself entirely. :bannana:
I had read Matt Weiss's article at www.stoptech.com about 'the warped brake disc and other myths' (thanks for the reference, Satch, everyone should read it) and am now pretty convinced by the suggestion that either pad imprinting or uneven deposition of pad material caused thickness variation and heavy vibration under sharp braking. Anyway, I did ten heavy stops in succession from 70 to 30 until I could smell the coffee, sorry brakes, and the problem cleared itself. Maybe I was just lucky.

 

[glojo]

Is there no where on the 210 that is NOT prone to rust?

Glad to hear you have cured the problem, I was just about to suggest the very same thing. Fingers crossed it has gone for good,
John.

 

[C43AMG]

My Front discs on the C43 where £ 160.00 each.

 

[Rory]

This (disk rusting) has been a problem on my wife's last 2 cars. She doesn't use them much, and then only drives very locally. I was shown one of the sets of disks and the garage told me that once rust builds up it tends to wear the pad away so that part of the pad never touches the disk, therefore never cleans it up. This become self perpetuating until most of the disk surface is rusted. It ended up that her car was braking on a band of brake disk about half an inch wide, and the disk looked pretty horrendous.

 

[fuzzer]

reading this thread , i got curious about my 13" discs on my car.

Got a price at which i was quite pleased with £62.86 each :O wow