Of course it is a safety issue. I understand that very well.
This problem rears its ugly head only while driving on the
highway. In town it seems to be OK.
As I stated before I have other vehicles thankfully it is NOT
my only mode of tranportation.
As an x factory trained mechanic (Porsche,VW, Audi,Mazda)
and current Aircraft A&P licenced mechanic,I think I know about turning wrenches a little bit,This auto as stated before is my toy and all I was
looking for was some ideas about how to solve this problem before
I dove head down in to it. Towing it to the nearest dealer was not
my idea as to how a do it yourselfer operates.Perhaps the time will
come and I will wave the white flag but I think it is a little premature.
Thank You very much for your relpy and your concern for a fellow driver
on the road is appreciated. Thanks Again Mr-tuanis........

I hope this helps you some. I had a very similar problem recently with a "76 model Corvette, mine turned out to be a faulty brake master cylinder. The vaccum brake booster may also be suspect on your Mercedes but I'd start with the master cylinder. I wonder if someone here has a test method for the msater cylinder?
Al

__________________
2007 Mini Cooper 4K miles
1993 300E 2.8 120K miles
1961 Morris Minor 42K miles
1965 Morris Minor 23K miles
1997 Ford F150 235K miles
1987 Ramcharger 202K miles
1984 Chevy C-30 farm truck 88Kmiles
1968 XKE 59K miles
2001 Harley Softtail
2003 Harley Roadking

The issue sounds like failed brake hoses acting as one way valves plus contaminated fluid.
By this point there is a 90% chance the calipers and rotors are junk.

Brake:
http://www.peachparts.com/shopforum/showthread.php?t=142411



As a new member, there is no way anyone would know your DIY level...

My concern is for you and other innocent people that may be maimed and/or killed.

Note:
The following is FYI data for the education of younger members, as to how serious the issue can be.

The car is not safe to drive on public roads, as per your description, and depending upon how the prosecutor views your credentials, the charge would be gross negligence as to amount to a willful or depraved indifference to human life, (if anyone died) Vehicular manslaughter or Murder charge in the state of Michigan.

One of my co-workers wife used to have a geo i think that exhibited similar symptons as yours. After a bunch of work that didn't make a difference, they discovered that the brake fluid has transmission fluid in it from someone who didn't know what they were doing. the power brakes would allow the fluid to be pushed to apply the brakes but the brake fluid collapsed the lines to where the brake fluid wouldn't return and would lock of the brakes at any given moment. so new brake lines and all new componets plus fluid cleared up that problem.

__________________
1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual

Thanks to All for the replies. In special to Whunter (super Moderator)
the worn brake lines acting as a one way valve is a problem I heard of before and perfecly plausible and /or applicable on this case.
Yes you are right the R/F disc is almost gone and the pads are approx
60to75% worn. I have NEW disks, pads,hub bearings and caliper rebuild kit
soooo this auto will go in to my garage and will not come out on the road
until it is repaired properly.I will look in to bleeding the system and will
most likely replace the brake lines with steel braided ones(perf prods)
I do not want to replace all the brake parts mentioned above and have the new rotors ruined.It is ALL I was trying to avoid. Such as an ABS egaging
when it is not supposed to (common on some aircraft).
As for the dealer tech's, mechanics,I'm sure they have their place and no
doubt SKILLS. But the nearest MBZ dealer wanted $1800.00 to fix a miss on My Ladyfriend's 280 ce and I was able to repair it for approx $350
quite a substantial savings (not to mention fringe benefits).
Well thanks to all again and keep those ideas coming.Mr-tuanis