I need advise bad. My vacuum pump failed this past week while my wife was driving the car. It apparently broke while on the interstate and presented no real symptoms until it was time to hit the brakes (i.e., lost power breaks) Since she was out of town, we figured a vacuum line had just come off or the like....long story short, she continued with her trip and just used a lot of leg strength for breaks and the shut off level on the engine to turn it off...the car probably went another 100-150 miles before getting back home.

I've since determined it was the vacuum pump that was the culprit, not any vacuum line leak or the like. Got a new pump and in the process of putting it on now. Removed the old pump and sure enough it came out in pieces. I'm pretty sure I have all the pump parts accounted for, but have now discovered a chain guide (I think?) is sheered. Specifically, you can see a metal chain guide in the bottom of the vacuum pump area....the chain guide appears to be broken with a 1-2" piece still surrounding the chain, but unattached a presumable lower section of the chain. Essentially, I can slide the broken piece of the metal rail up and down along the chain.

Question #1 - I'm no mercedes mechanic (just engineer that likes to tinker), I assume that is a chain guide I am seeing, yes? Question #2 - I assume this is a disaster waiting to happen and the entire section of guide needs replaced, yes? Question #3 - the stroke curve on the injection timing device appears non-smooth and perhaps scoured/scored...I assume if it isn't smooth as new, it needs to be replaced too, yes?

Thanks for the help. BTW, this is my 2nd round of vacuum pump failure.
svengruber

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1993 300D 2.5T
1968 280SL - sold

I think your assumptions are correct.

You already had a lager chunk of luck that the Failure did not take out your Engine.

Why take any more chances; fix it right.

On your Engine is the Fuel Injection Pump Timer attached directly to the Fuel Injection Pump?

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84 300D, 82 Volvo 244Gl Diesel