camexican

I’ll try and keep this as short and sweet as possible. Here are the facts.
2004 ML350 – 63,000 miles, wife’s car, I drive it every few weeks
One day I got in and the brake pedal felt spongy and did not firm up the way it usually does
I opened the brake fluid cap and it looked like coffee
I took it to the MB dealer where the car was purchased and gets any service that I don’t do myself and asked them to flush the brake fluid
They flushed it and my wife took the car home (she is not good with cars)
A few weeks later I got in and realized the brakes were the same as before the flush
I decided to put new discs and pads on (aftermarket)
When I finished there was no improvement, so I bleed each line once
No air was visible but the brake feel improved a lot, so I took it back to the MB dealer for a second bleed
They argued at first saying all MB’s have spongy brakes, but after a test drive agreed to bleed it
After the bleed it was worse. Now the pedal goes to the floor and then some
They suggested a new master cylinder and I agreed
Result was that the pedal still went to the floor.I had to leave the country and won’t be back for a month, so I told them to do whatever it took to fix the car and to NOT call my wife till it was safe to drive.
It has now been over 20 more days of trial and error at the dealers. They have replaced every single component on the system and had the nerve to call my wife to pick it up yesterday because it was “fixed”. She took it for a test ride and was able to hit the floor with the pedal without stopping the car!
She spoke to the manager for a third time. He claims they have never seen anything like this and are willing to return all our money and give us the car as they can’t fix it, WTF? The car was worth $10,000K and had slightly soft brakes when we brought it in. Now it’s an unsellable POS that can’t be driven.
I’ve approached MB mechanics on justanswers.com and any advice they have given has already been tried by the dealer. I’m at my wits end. The rental bill for my wife’s replacement car is nearing $2,000 and I’m 2 weeks from getting home.

Have any of you ever run into something like this before?

Odd Piggy

Have never had a problem like yours before, but may have had a dealer like yours. I had a dealer that I suspected of charging for work and returning the vehicle (not our ML350) without actually doing the work, so I clearly marked parts for identification that needed to be replaced. When the car was returned, the parts with the obvious marks were still on the car, but I was charged for the work. When I confronted the dealership management with the evidence, they refused to recognize the issue saying only, "If our techs say the part was replaced, then it was replaced." Needless to say, that was the last trip to that dealer that any of our MBs made.

I suspect that all MB dealers are not like that, but the next closest dealer is just too far away. I found an independent shop that services European cars and began going there. It is small and the owner will discuss any problem you have in whatever detail you want. He and the staff are very knowledgeable and will also give you the details of the trouble shooting and repairs made. If a repair fails to solve the problem, I have never been charged for the second trip. He also does things like replace a fuse or reassemble a connector for no charge.

Don't know your local situation, but maybe you should look for someone like that flying an MB banner. Your wife seems to be like mine and not mechanically inclined so you need someone who can be trusted. Brake systems on the ML350 are not overly complicated, so a solution should be available.

camexican

Thanks O.P. I may have to tow it to Laredo TX if all else fails.

Maj. Dundee

I believe that someone at the dealership or someone previous to the dealership used DOT 3 brake fluid instead of the required DOT 4 brake fluid.

When the two are mixed, it results in the deterioration of any O-ring or rubber component in the brake system, hence the color of coffee of the fluid.

Odd Piggy

Maj Dundee may have described the root of the brake problem. His posts have helped me a number of times in servicing my ML. If that is the case, just bleeding brakes at the wheels may not be sufficient. Reverse flush may be better, but the calipers may need to come off, be disassembled, cleaned and rebuilt to remove all debris. Deteriorated rubber components in the brake lines can cause a catastrophic loss of braking at any time without warning.

BTW-Read your post in "How many miles…" and you are having to replace things that most of us will never touch in the lifetime of the vehicle. Other things are being replaced rather early. My MBs have lasted 2 to 3 times as long as anything else I've owned and I'm not prone to compulsive maintenance syndrome. You may have a service situation that you need to get away from and how convenient that is may determine whether or not you can stay in the vehicle. Unfortunate as the W163 can be solid reliable transportation (although the cupholders look like they were designed by summer interns).