SleepersRock

Ok. So I've had an issue with the brake pedal having long travel and the car not stopping on a dime like it used to. I got around to replacing theMaster Brake Cylinder as that was the most likely cause. A brand new MBC did nothing! I still have long travel and soft pedal feel. Dealership says the only other thing they can think of is the pads (Akebonos) not stock. I don't buy that since this occurred when I had stock pads also. They did some test where they clamped the lines to see if it was the booster and or calipers but that came out negative. Then they told me some cars just do this and that had an ML55 w/the same issue had everything replaced by MB USA and that still didn't fix it. Since this happed slowly over time it's gotta be a defective something I just don't know what else to do. Any ideas?

Yacht Master

This is caused by air in the brake lines. The only way to get the air out is to use a power bleeder. The old two man pump the brake release the bleeder petcock will not work on a W210. As I recall the power bleeder needs to be capable of pressuring the reservoir to 2 BAR 29 PSI this dose two things.
1. Opens internal bleed ports in the ABS
2. Forces all the air in the lines that run vertical, to go against nature and flow down and out, by means of pressure and overwhelming volume.

You have had this for some time now.

https://mbworld.org/forums/w210-amg/...-question.html

SleepersRock

Yup I've had this for a while. The dealership claims the first thing they did prior to swapping the MBC was to bleed the brake lines. Is it possible that they did this two man pump job and not power flush the lines (or flush it at 15-20 PSI not 29-30 PSI)? Shouldn't all dealers have this equipment? Assuming they did that and pedal is still soft where do I go from there? I will also try and have an Indy shop do a power flush according to yachtmasters post. Not being able to drive fast cuz you fear the car won't stop is driving me nuts.

SleepersRock

I think I fixed the brakes myself on accident. I nearly hit a car after he cut me of and braked while trying to enter the freeway exit lane I was in during rush hour. Pedal feel was soft and travel was long when I slammed on the brakes and felt the ABS vibrating. After exiting the freeway I noticed that the pedal was much firmer but still not like it used to be.

For some reason I got an idea that maybe there is/was an issue with the ABS or something that it controls, so I headed to a deserted farm area where I normally do runs with others. I floored it to anywhere between 60-80 and then slammed on the brakes activating the ABS to a complete stop about 4 times. Each time the pedal feel hardened and pedal travel decreased.

I've been driving for a week now and the brakes are working properly like they should have all along. I have not done anything with the brakes after my last first post in this thread.

Could hard braking and activating the ABS force fluid into the vertical lines per Yacht Masters suggestions? Any other possible explanations for this?