On my '81 300D, the piston-style vac pump died a couple of days ago. I was away from home at my girlfriend's remote cabin so I pulled the pump and left the car so I could get home and figure out my plan of action. When tinkering with the pump, I found that some bonus pieces fell out of the the main entry port into the pump (the spot where the brake booster line connects).

After examining the pieces and doing some research, I've realized that it is the main check valve that came apart. I think I have all of the pieces (the small metal piece that is shaped like an X, a small spring and a small plastic plunger). Looking at the design of the pump, I would think that it would be impossible for any other pieces (if there are other pieces) to get past the other internal check valve and to the other side of the piston and into the crankcase. Does anybody have any experience with this type of vac pump failure? Have I found all of the pieces, and am I right in my thinking that it is impossible for any other pieces to have made it into the crankcase?

As the car is 2.5 hours away from home, I don't have an oil pan gasket, and I'm already missing nearly an entire week of work until I get this resolved I am trying to avoid doing any unnecessary work or delaying my downtime even more . . . otherwise I'd just wait another day or two, get the gasket and do it anyway.

My brand new vac pump should arrive tomorrow morning and I plan to make the trip down to install it. Decided that the piece of mind from the sealed bearings was worth the additional cost over the rebuild.

Thanks,
Eric

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1981 300D - {172,000}
1971 220D {Sold to TomJ}

In the unlikely event anything got past the check valves I don't think there is any way it could get past the piston.
I wouldn't worry about it.

Danny

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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My new pump arrived today . . . but I think I may have misunderstood another post I read. I thought that ordering a new pump for my car would mean that I'd get a pump with sealed bearings . . . this pump has the same bearing system as my old pump. Looking back through the archives, it seems the post I read that led me to believe this was about a 603, not a 617.

Does anyone know if the pumps for the 617s are available with an improved bearing design?

Thanks,
Eric

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1981 300D - {172,000}
1971 220D {Sold to TomJ}

That should be everything. I have seen that problem several times; none of the parts of the check valve made it into the working portion of the pump.