possible vacuum problem?

[fz500sel]

'85 300D (271K) The other day I was on my way to work and after about 20 minutes of driving, I was about 1/4 mile from my work and I noticed that the vehicle started shifting hard. When I parked it and went to shut it off, it didn't shut off right away. After about 5 seconds it shut off. Then when I exited the vehicle and went to lock the doors I noticed that the central locking system was barely working. I thought to myself, "Just what I need--a vacuum problem!"

Well when I left for the evening, it started up fine, shifted fine, shut off fine and locked fine. As a matter of fact, it has been working fine for 3 days now.

Is this one instance of vacuum problem, something that I should be concerned with? It was raining heavily that day and I did have my usual puddle in the rear passenger footwell. Does the vacuum lines run along the footwell raceway with the electrical lines?

Thanks guys!

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FrankieZ
84 500SEL EURO 87K
85 300D 267K (and still goin' strong)

[This message has been edited by fz500sel (edited 06-07-2000).]

The vacuam lines do run through the rear floorboard, but I can't imagine that causing the problem you described.

BTW I dealt with back floorboard water after rainstorms for years. Finally thanks to this forum, I cleaned out the drain ports under the hoodhinges and just inboard from there with a piece of baling wire (for city people, a coathanger would probably suffice) and have yet to have reoccurrence of the problem.

Good luck,

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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

[Benzmac]

It sounds as if you have the check valve in the vacuum pump starting to fail. It is the one that the brake booster vacuum line attatches to.

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM