LukasBMW

Something is wrong with my ABC suspension. Here is the series of events:

A month ago - As I started the car, the red warning lights came on telling me "ABC". I started and re-started the car several times, and the warning went away. I did not notice anything wrong with the suspension as I drove it home.

Two weeks ago - The red ABC warning light would come on every time I hit a significant bump while driving at speed (50mph or higher).

Today - I have noticed that the car is having trouble leveling. One rear side is higher then the other. Additionally, even though I have the car set on position 1 (one red dot), the rear of the car is at a very high height...easily a height that would be standard for position 2 (2 red dots...the highest setting).

The car also feels VERY stiff regardless if the car is in sport or comfort mode. Comfort mode is now as stiff as the usual sport mode and sport mode feels almost as stiff as the race suspension on my old BMW 325is.

Despite all the weird **** going on, there are no constant warning lights...other then the brief illumination of "ABC" in red when I hit a bump while driving.

Any idea what is wrong?

I'm so glad this is still under warranty. Whatever the problem is, I bet it will be expensive to fix. LOL.

sprins

I'm no MB mechanic. But if I had to guess I'd say one (or both) of the ABC valve blocks is malfunctioning. If the level weirdness is only on the rear axle it's the rear valve block.

edin_sl55

My car had trouble leveling and would take a significant amount of time. I replaced the pump and cleaned the valve blocks now its like new. My advice would be to replace the pump if you have the tools it is simple. If you decide to go this route let me know I have a brand new refurb. abc pump. I ended up receiving 2 from a distributor.

sprins

How does one clean the valve block?

edin_sl55

Its simple take a look at this video.
http://www.youtube.com/watch?v=vqkfz2LRoPQ&sns=em

alx

Correct. I suspect leaky valve block. They are easy to disassemble, clean, replace o-rings and put back to normal with minimum effort. I have yet to see a valve block that has burned out internally- they all just clog the fine mesh inside them, develop leaky o- rings or just need a good clean with brake fluid. I' ve done a couple with great success.

sprins

Interesting. I was thinking of replacing the 10 year old valve blocks too because of sagging. Never knew they could be refurbished this way. Thanks!

LukasBMW

Good info. I'd totally look into that if I didn't have a warranty. But for a $100 deductible, I will let the dealer mess with it while I cruise around in a little C250 loaner.

It's amazing that the dealer can rape us for $4k on a part that would cost a few hundred to fix. It really is borderline extortion. If you buy a Benz with no warranty, you best have a good/honest indy shop lined up.

rlh23

I really think this board is as important as a good indy because we can bounce repair costs off each other and have some knowledge about a repair before we go to the shop. I agree though, a good indy is better than any MB dealer.

alx

a valve block redo is about $25 worth in o-rings and a can of brake cleaner.

removal and reinstall of valve block is trivial.

sprins

I recently had my trusty supplier MbenzNL and his shop work the ABC refurbish on the front ABC valve block, and no more sagging for my SL after some hours.

Thanks to the information in this thread I saved a bundle (since MB scenario would be replace instead of fix).

Thanks all!