Ruben, how can I tell if I have the "new" or "old" style vacuum pump on my new-to-me 603? I have some work to do (water pump, belt tensioner) and might as well do the vacuum pump too if there's something to be gained.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

When this is done do you rebuild the old vac pump, put on a used or new/rebuilt?

I keep reading about needing to do this after so many years. Is there any indication when it is time?

My '81 300D had 400k and I never touched the vac pump. Was I just lucky?

Thanks.

There are many who say that the old-style vacuum pump (cover without bolt heads) should be replaced, period. Do not pass GO, just replace it. There have been a few failures and if a part gets into the oil pump (if driven a while that way) or into the timing chain (more immediate) it can potentially destroy the engine.

There have also been failures of the new style.

I have followed this advice, and replaced mine in past cars, removing the perfectly good old-style and tossing it. It is supposed to be non-rebuildable.

Currently I have changed my tack. Whether it is a good idea or not, others will debate. Anyway, I still have the last one I removed, and am building an engine for my car, removed the one currently in the car also. They are both perfect, work well, bearings smooth and tight, I see no reason to toss them and will be re-installing the vacuum-pump. This after spending thousands on upgrades? It seems to me that inspecting a part, finding it to be good, and reinstalling is what keeps aircraft in the air, especially since we know the failure mode is for the bearing to wear out and lose the cage. It can be inspected easily.

So replace yours, it is good insurance, I'll run mine another year and inspect it, or replace it next time I need a belt, we'll see.

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Gone to the dark side

- Jeff

The one you took off was the new style, why did you take it off? How many miles were on it?

Thanks Jeff.

That's my question as well, the removed vac pump appears to be the new style which would suggest that someone already replaced the original, do you think it really needed to be replaced?

steve a

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Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
+ others