My W123 stops nicely but after a couple of seconds on the brake at a red light there is a rush of air sound and the pedal pushes back up against me forcing me to press harder to maintain a stop. Y'all think this is the diapragm in the bosster or possiblr just the one way check valve? It will slowly go back down again and be easy to press if I sit there longer. Thanks, Paul

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http://img212.imageshack.us/img212/5...andbenzqj3.jpg1979 W123 300D Silver with Blue interior

Test the valve and see if it's the problem. You should only be able to blow through it one way.

I would suspect a bad booster. Did you have any fluid leaking from the MC that could have flooded the booster?

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Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

No, doesn't look like any leaks ever. It will sort of "breathe" under foot. You are probably right though. I am suspecting booster. I hope there is a rebuild kit for them. Paul

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http://img212.imageshack.us/img212/5...andbenzqj3.jpg1979 W123 300D Silver with Blue interior

I've never seen a kit to allow the DIY'er to rebuild the booster. You can buy a reman unit for MUCH less than new (around $150 IIRC). They aren't too bad to replace either. 4 nuts holding the booster under the dash and the 2 nuts holding the MC to the booster. If you are concerned with cost, maybe try one from a junk yard that has no evidence of fluid leaks on the front.

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

Good call. I am going ot the yard this weekend. I will look. Paul

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http://img212.imageshack.us/img212/5...andbenzqj3.jpg1979 W123 300D Silver with Blue interior