Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1 (Edited)
dear all,
I have just replaced my Third set of Genuine Mercedes Front Discs and pads.
- hardly do very much millage, and as I am now on my third set in 12 months, I couldn't drive more carefully (late at night, so not very much traffic, allow the car to slow itself towards a stop, VERY Gentle braking, and never had a 'hard' or sudden stop.
It has just passed a new MOT, but already they have warned me there is a very slight 'run out' on the front brakes again.. to be perfectly honest this can (just) be felt if your very,very, particular (it was picked up by the MOT computer).

I can not understand why? - the garage (very reputable) suggested they had seen this only ever once before, but that car was sent back to the main dealer, so they never discovered why, but thought (maybe) in that case it was 'something to do with the hub' ?:confused:

does anyone have any idea what may be causing this?
Brand new Genuine Mercedes are parts fitted, and the car is driven very, very gently?
 

·
Registered
1994 C280
Joined
·
111 Posts
You may possibly be driving it "too" gently. The owners manual will say to make periodic hard stops (without endangering other road users). Also, do you wash you car straight after driving it? Automatic car wash machines? They will shoot cold water on the hot brakes = bad.
 

·
Registered
'98 C230, '08 C300
Joined
·
155 Posts
Please update your profile so we know what and where.

MOT - Googled MOT and came up with Great Britian Ministry of Transport. Is that correct?
MOT test - Wikipedia, the free encyclopedia

What do you mean by 'run out'? If your 'very reputable' garage has replaced three sets of disks and brake pads in just one year, well, better look for another garage, as they are NOT reputable!
 

·
Registered
2010 E350, 2005 Tundra Sold the 1998 C230
Joined
·
322 Posts
Very easy to check runnout, you can get a dial indicator and magnetic base from places like harbor freight for about 20 bucks. With the base on a part of the linkage and the needle riding the disk (wheel off) spin the disk and see how much on average the disk deflects the needle. That is your runnout. Usually when rotors warp due to heat or cheap chinese castings that will cause runnout and a pulsing sensation in the brake pedal. If you are buying name brand rotors (OEM Mercedes should be great), then rotors warping should not be an issue.

Other than a bad rotor, you can also check the front wheel bearing. It should turn smoothly with no play. They can be cleaned and repacked with grease, I think there is a special "Mercedes green grease" that is called for, (there is always a special Mercedes something :rolleyes:), but it is easy enough, again with a bearing repack tool also available at places like Northern or HF. Just be careful of working around the ABS sensor if you do tackle the project yourself.





bearing repack tool:
 
1 - 5 of 5 Posts
Top