Rotors "Destroyed"?

[Chayro]

I have a 98 ML320 I bought in Dec. 04. Prior to purchase, I brought it to my personal mechanic who told me that I was going to need front pads after a few thousand miles, but otherwise ok. The person I bought it from had it serviced at Mercedes in Sept. 04, when she had 4 new tires installed as well as an alignment. Since that time, about 5000 miles were put on the car. The brakes feel fine and there is no wobble or anything. I had it in for an A service today and the writer told me the brakes and rotors were "destroyed" and needed replacement. I found this odd because I was experiencing no problems and I knew they couldn't even have taken the wheels off because they didn't have the key for the wheel locks. Is it possible they're correct? I thought you had to check the run-out and all that stuff before you could even tell. I can't believe that if there were something wrong, they would have noticed something in Sept, when they pulled the wheels. Since I bought the car in Dec., I put at most 2000 miles on it. What do I need to know? PS - my receipt reads that no fault codes showed up on the computers and the car road tested without occurences. Thanks for your help.

[stevebfl]

How bad do they have to be? I can probably see bad rotors from twenty feet out.... through the wheel. Depends on the problem. Knowing that MLs use up a set of discs atleast every second set of pads helps in the remote analysis. Stick your hand through the wheel and feel the lip at the edge of the disc (that an experienced tech can see). The disc is flat when new. There is a limit to how thin the rotor can get and when you know where they start and can see more lip than the wear tolerance, it gets real easy.

[jayb79]

Service writers are worse then used car salesmen.

I took my wifes BMW to the dealer to have the heater core replaced(could not find anyone else that would touch it) and after she picked it up she was all in a panic because the service writer told her the front and rear rotors were junk and her brakes could fail at any time. Needles to say i had to jack up the car and check it out and yes the pads and rotors were worn but they went for another 10k before i replaced them(front only). I can not imagine having to take my car to be worked on by a dealer on a regular basis.

I would take it to an indy if you are realy woried about it. But it sounds to me like you should be fine.

[mpolli]

The rotors probably do need to be replaced. But I would leery about a service dept that throws around such stong terms as "destroyed" when they should really say "worn and should be replaced". I would want a different service rep at least.

Mike

[Melcher]

I agree with mpolli's comment about their terminology and how much that reflects on their professionalism. get a second opinion.
And to answer one other question. Mercedes Benz produced thier own brake disc micrometer that can measure rotor thickness through the spokes of the wheel. So Tech's do not need to remove wheels to get an accurate measurement of your brake discs (rotors).

[Impala]

"I knew they couldn't even have taken the wheels off because they didn't have the key for the wheel locks."

Not to dispute Steve's advice that experienced techs actually don't need to take the wheels off to read the rotors...

I think dealers may have some sort of master wheel lock keys.

There's no wheel lock on our W124. But our family van does have such and we never need to hand the wheel lock key to the dealer -- they're still able to take wheels off to rotate tires, etc.

[Jim H]

Originally Posted by Chayro

...I had it in for an A service today and the writer told me the brakes and rotors were "destroyed" and needed replacement. I found this odd because I was experiencing no problems and I knew they couldn't even have taken the wheels off because they didn't have the key for the wheel locks. Is it possible they're correct?

You might ask them how they made that determination and see if it makes sense to you.

They can't tell you if they have 10 miles or 10,000 miles left, since they don't know your driving style and probably didn't take an exact measurement.

If they are worn significantly and didn't tell you to replace them, they are then opening themselves up for grief/lawsuits later... not necessarily from you as an individual, but the public in general.

Best Regards,
Jim

[onesixthree]

as already mentioned, never trust the dealers when it comes to brakes. it's sad how dealers do this to make money but they're actually falsely perpetuating bad reputation for MB vehicles eating brakes. many mb owners are duped into getting new pads every 10k miles, but they need to learn about their cars better. rotors should be changed on 2nd set of pads i believe.

[Chayro]

This info has been extremely helpful. If indeed, MB recommends rotor replacement after 2 sets of pads, I have no doubt my 320 is due. As I only drive 3K a year, I highly doubt i'll see another rotor replacement. I'd like to give my private mechanic the work. Is it an unusually complicated job, or is it just like rotors on any car?

[wbain5280]

Personally speaking, I would call rotors and pads destroyed if the rotors were overheating and were blue and/or the pad material was gone and the backing plates were scraping the rotors.

But, that's just me.

[nglitz]

I had a Toyota dealer's service writer tell me that the shoes (drum brakes) on my wife's Camry only had 5% of the lining left. That seemed like a pretty specific measurement, so I believed him.

I bought a new set of shoes & pulled the drums. The first one didn't look even half worn. Maybe they only looked at the other one. So I checked the dirt buildup around the plugs and wheel studs. They never even pulled the drums to look.

I put the shoes on anyway as the job was half done just to take a look. The old shoes had LOTS more than 5% left. More like 75%.

The guy flat out lied to me so he could get more money out of my pocket. What's new?

[csnow]

You can certainly tell without pulling the wheels, and it may indeed be time for new rotors. Nothing particularly suspicious about this.

OTOH, brake jobs are a very high margin item, and there is incentive to throw one in while they have the car in hand.

[lee polowczuk]

i stopped doing my own brake jobs years ago...thinking my families safety was the most important thing....

then a few years ago.... a service rep at Goodyear said my wife's expedition needed brakes.... i looked at the previous bill..and it was only 20k earlier... i thought this was crazy...

anyway, I bought the pads and decided to start doing them again myself.... I would say they pads had 50-60% left on each one....

I stopped going to others for almost any kind of work following that..... even oil changes...which i really hate to do...

[onesixthree]

not only are dealers dishonest about needing new pads but they also charge twice as much as indy shops