Tump43

Well,

I took my C55 in to the dealer for an inspection, some warranty work, a coolant and brake fluid flush, and to tighten the emergency brake.

They called me and said they couldn't tighten the emergency brake because my rear rotors were cracked (and that they wouldn't pass me on inspection either). What!! I don't see how the two are related.

The rears are genuine MB AMG SLK 55 rotors and are only 6 months old. I drive less than 10k miles a year.

The only thing that happened immediately before the emergency brake stopped holding the car was, at the Dyno shop, the dyno guy managed to wrap the rear tether around the e-brake cable and did one dyno run with e-brake partially engaged to the point where it started to smoke. After that the car felt and stopped fine, but the e-brake would not hold.

The dyno guy claims that his actions could not have cracked the rear rotors because what he did was as if he drove less than a quarter of a mile with the e-brake partially engaged; and, in any case, that amount of driving could not have ruined the e-brake either.

What do you guys think? Is the dealer if full of sh-- because I upgraded my brakes? Did the dyno guy mess up the brakes? or I was just unlucky enough to have somehow cracked my rear rotors driving in the cold weather? and how can the rear rotors be related to the e-brake?

Any help would be appreciated.

Tump43

By the way the warranty work was: 1) Command stopped working, no audio at all for nav, cd, ipod or radio. Dealer stated a leak in the trunk shorted out an electrical component that controlled the audio, and that would have to fix the leak and replace the component; 2) the driver's seat bottom warmer stopped working (dealer replaced this last winter, and will replace it again); 3) the shift boot has a rip in it (dealer said he would replace it).

Kar don

brake drums do not dissapate heat very well... do you really know how long the ebrake was on for?

c32AMG-DTM

Tump43,

First, let me say that really sucks. IMHO, my guess is that the dyno guy isn't being completely upfront about this... or is down-playing it as a CYA move. If you consider the speed your rear wheels are going on a full dyno run, this would probably be more like doing a 1/4 mi run with the e-brake on than merely "driving less than a 1/4 mile" - which I'd think could very likely toast the parking brake, and MAYBE could lead to cracked rear rotors (but this is less likely, I'd think).

If I were you, I'd first push MB to replace the parts under warranty (typically, MB replacement parts carry a 12 month warranty for manufacturing defects, IIRC). If you say "hey guys, these genuine MB rotors are only 6 months old, and the car only has 5k miles since they were installed - and the front brakes do 95% of the work anyway... there's no way the rear rotors should be bad already unless they were defective" they might be reasonable and replace them.

If not, plan B would be to go to the dyno shop (owner, if need be) and say "hey, these were fine until the accidental dyno run with the parking brake activated, and now they're cracked - I like you guys, and give you a fair amount of business, but I honestly feel that this mistake is 'on you' and you should fix it."

Just my $0.02 - good luck, hopefully it'll be handled to your satisfaction one way or another...

MarcusF

In reverse order:

1. They are related because the e-brake and the rear rotor are the same part.
2. No, you didn't crack a rotor because it's cold outside.
3. Yes, the dyno guy killed your brakes. It wouldn't surprise me if the dyno shop offerred to do the work for you. Just remember, this is the same shop that "wrapped the tie down around the emergency brake cable", did a pull, and then said it couldn't possibly have affected the brakes . . . . . the brakes where all the smoke was coming from.

boohooramblers

This sucks man
Your dyno guy is a moron and he needs to bear the burden of replacement costs if you can't claim the 12-month warranty on MB parts.
Just out of curiosity - did you sign a waiver at the dyno shop releasing them from any liability while your car is on the dyno?

JToups386

Exactamundo! Absolutely correct. And to be honest, this is not MB fault or responsibility to fix under warranty. They are not liable for part failure due to ignorance of an outside installer. And, if you mention this happened on a dyno, they'll definitely shut the door on you. I honestly think you need to confront the dyno shop owner. There is not a doubt in my mind the two are related. Imagine the heat that was generated during the pull w/ the e-brake engaged. You're lucky there wasn't a flame.
Go to the shop and "encourage" them to fix it.

MarcusF

I was taught that when an engine has to be rebuilt, a cause must be established. That's because if I don't know why the engine failed, failure may reoccur. Brake failures are the exact same. I haven’t seen this rotor, but I have seen cooked rotors. I envision the dealer's brake tech taking one look at the rotor and thinking, "Hmmm, only one corner is cooked, the pads are still good, the rotor is cracked, and the parking brake shoes have been vaporized." It's not going to take long for the tech to figure out the parking brake was engaged on one side at Autobahn speeds. It may take a while to figure out why. Time is money. If it takes the dealer brake tech three hours to conclude the failure was not caused by a vehicle defect, the dealer should be paid for diagnostics.

The OP shouldn't have to do anything other than be open and honest. The dyno shop operator killed his rotor. The dyno shop, not the parts warrantee, should pay the expenses. As for a waiver, I don't know NY law, but if that happened out here in Der People's Republik of Kalifornia, the waiver would get tossed in court. If the engine spun a bearing on the dyno, the waiver would work. If the car came off the rollers, maybe. When the technician wraps the tie down around the "parking brake cable"? LOL! With me, the dyno shop would have two choices; (1) pay for the brakes, or (2) explain to a judge why their gross negligence should be overlooked.

c32AMG-DTM

Agree w/ everyone, with one caveat - isn't the parking brake only on one side of the car? If both rear rotors are cracked (which is what the OP states), wouldn't this potentially be a defective part issue?

Tump43

Looks like the consensus is to go after the dyno guy. This I will do. To bad though, he's a nice guy and I like the shop. I may just speak to the owner and have him decide. The dyno guy admitted tying off the e-brake cable right after it happened, I'm suprised he didn't offer to replace the rotors. The e-brake did not hold when I got home from the dyno run.

Thanks,