Rear Brake Disc Problem

[Andy747]

Hi all,

My 350 has 3500 miles on the clock and I noticed an odd squeaking noise from the rear when in slow right hand turns. Examined the rear discs and noticed the right one had corrosion on the outer 5mm. I took it into the dealer today and they have decided to replace both rear discs and pads. They have not seen corrosion happening on only one side before. May be a misaligned caliper or something.

I know Woolly has had problems with corrosion on his discs. My car doesn't sit for long periods though so it shouldn't be happening on my car - shouldn't really happen on any car if the discs are good quality!

This car really lacks in build quality. No other car I've owned has had such fundamental problems. However this is the first car were I've spent nearly £40,000. I fear this will be the last MB I ever buy[V]

[CMiYC]

<I>shouldn't really happen on any car if the discs are good quality!</I>

Actually the car's quaility has nothing to do with it. It is extremely common for rotors to rust. It depends on the materials used and the enviornment they are in.

You are correct that only one disc shouldn't develop a problem, nor should only one portion of it. However you are mistaken if you think a brake rotor that rusts is any sign of quaility. That's not quaility, its chemistry.

[Julien]

Were you told it was corrosion or rust (or is this an English thing [:D])? CNiYC is correct and almost all brake rotors are made of cast iron (Ferrari to Kai) and iron rusts. Corrosion happens on other metals but I believe that it isn't common on iron (unless exposed to a corrosive chemical).

You problem sound like it may be caliper and/or piston related.

[Andy747]

They said it was corrosion but it looks like rust to me. The pad is definetely not rubbing on that portion of the disc so it's probably a misaligned caliper.

The discs on cars may be all the same - I've owned a few cars! However I've never seen rust build up on one disc and not the others! The fact remains that this car is poor quality. Yes all discs will rust but not as they have done on my car. The fact that the car needed an entirely new rear axle 4 weeks after delivery, the fact that the paintwork had bubbling on the paint which wasn't detected at the factory and many other problems people have highlighted here shows the poor build quality.

[GG AD 600]

Andy, I know that´s really annoying ! I mean we´re not talking about complicated stuff here it´s just the basics of building a modern and reliable car.

I also have problems with noise (squealing,grinding noise) from the brakes. The advise the dealership gave me: " As long as no brake wear light comes on it´s safe to drive !" I guess that unacceptable for such a expensive car.

It´s bad enough that the car seems to have certain quality probs, but it´s turning even worse when you bring it to a dealership to help you.

OT...

Still I don´t see any too much alternatives on the convertible car market.Drove the BMW Z4 before which was really bad concerning qualitiy of the interior. Rattles all over the place after only a few thousand kilometers and a lot of noise from the roof.

The Lotus Elise was a fun ride as a motorcycle substitute but nothing I`d like to have as a daily drive.

I liked the Boxster a lot, but again as a daily ride the SLK is better. If it was just for the weekends I would definitly drop the SLK for the Porsche Boxster.

Still waiting since 3 month for the Mitsubishi Evo IX Test Drive.Gonna be interesting but no convertible.

Final thought...

If you have a look at the "Fast Fleet" Report in EVO Magazine you get the impression that finally it doesn´t matter if you drive an Aston or SLK. The problems stay the same...

[V]

Andy