robertjm

Hi all,

Yesterday I replaced the front rotors and pads on my 2003 Mercedes ML500. Using Zimmerman rotors with Duralast Gold Ceramic pads. When installing I spread some brake paste on the backs of the pads before installing them.

Now, there is a pronounced scraping noise when driving that was not there before, which seems to get slightly less noisy when getting up to highway speeds (during the test drive). Brakes feel good otherwise. A visual inspection on the outside of the rotors is not showing any type of gouging, thankfully. But, it was too late to pull it apart last night and check all the sides.

Figured I would ask the forum when I first got up before tearing the whole thing apart, in case there were some obvious things to look for first.

Robert

khomer2

Sound clip?

robertjm

I'll try and get one this afternoon. We're going to jack up the front and check the brake dust shield, in case that got bent when we were banging at the rotor to break the seal.

In the FWIW department, I'm not sure I remember hearing it when I drove in reverse.

robertjm

Didn’t get a good enough sound clip. But, we’ve figured out the scrapping sound is coming from where the brass metal brake clip is in contact with the rotor edge. You could see a little silver gray deposite on the clip when I pulled it off.

So far we’ve tried bending the clip to try and get out of contact from the rotor. But, to no avail.

The guy whose helping me eyeballed it and he says the Zimmerman is bigger than the rotor that was on there. Or so he thinks. But, he’s just eyeballing it.

khomer2

Oversized (diameter) rotors?

robertjm

The site I bought them from says they’re 345mm, the same as the Genuine MB are.

khomer2

It may say 345mm (which is correct), but did you measure them? (dont take their word for it)
Ive heard other situations where the parts packaging info is correct and then measured to be wrong (brake pads as an example)

very strange.

EDIT: update.....

ML500 brakes;

Front Rotor is:- (303mm dia.) & (26 thick.)
Rear Rotor is:- (285mm) & (15mm thick.)

*in some ML500 models, all brakes are the same with ML55, which is...

Front Rotor is:- (345mm dia.) & (32 thick.)
Rear Rotor is:- (330mm) & (14mm thick.)

*it depends of your ML500 brakes specs

SO it seems your ML500 most likely had/has the 303mm dia.

IF you do decide to keep these larger dia ones, you can swap over to the larger ML55 calipers.

robertjm

Thanks for the information!

We ended up beating the brass metal clip up till it cleared the rotor, and there is no more noise. 42mm is a pretty big difference! Unfortunately, we didn't measure the new rotors, and they're on the vehicle. However, I still got the old rotors in the back of my vehicle, so I'll measure them in the morning to see if they are the smaller diameter one.

Have a great night!

Robert