check valve internal gone
 

I have a 1984 300d with around 315k miles.
I lost vacuum yesterday. I pulled the metal vacuum pump check valve and it was hollow. A clear open path to the vacuum pump.

All of the internals must have deteriorated and then sucked into the vacuum pump.
It looks like I can remove the vacuum pump from the block with allen bolts or remove the front plate which is attached with phillip head screws.

That parts are probably jamming up the piston in the vacuum pump. I put a new check valve in but still very little if any vacuum.

Any thoughts?

Thx

pete

the pieces are too big to fall into the pump. they usually end up in that upper elbow piece where the vacuum hose screws on to. you can get something to fish them out of there.

I didn't see anything when I looked into the hole. Maybe I'll fish a small magnet down there. I also have a mityvac pump that I use to do my brakes. I could fish the black tube down while squeezing the handle.

Thx

pete

To be on the safe side I'd remove the vacuum pump and make sure nothing is trapped in there. You must have heard / read about the OM617 and its vacuum pump problems before right? (meaning how if it goes it sheds junk into the timing chain and ruins the engine)

Should I remove the allen bolts from the block or just the plate with the phillip head screws?
Thx

pete

Not the screws that hold the cover plate on the pump itself - remove the whole pump from the engine => that should be the allen / hex head screws / bolts that go into the block.

This is making "extra work" but I for one would like to know for sure that nothing is in there - may be you want to wait for the advice of others? Do a poll? Have you seen Beagle's replace your vacuum pump bearings thread before?

I didn't know replacing the vacuum pump bearings was a maintenance item.
I will read up on it.
Thx

pete

Well arguably it isn't - but for the age of the parts it is something that I think we should all consider (at the very least). Do you need a link to the thread?

The Check Vlave is what the Arrow points to in the pic.

Not reasonably possible. You should be able to fish the check valve components out of the intake port with a piece of bent safety wire.



That's because the old check valve parts are obstructing the inlet.

Neither. Leave the pump on the engine.

I think I need to clarify the advice I gave above - I've not been clear - I'm a bit concerned about the little vacuum that is now being produced than I am about the missing check valve.

Because I'm super cautious I would remove the pump and check it out. But as I said above it is making "extra work" that perhaps is not necessary. I understand completely that what I would do isn't necessarily what others might. I tried to give fair warning - looking back perhaps I wasn't clear enough.

And I forgot to mention something else!

My experience of removing the cover on the front of the OM617 vacuum pump has not been a good one. In my case the screws were corroded into place and needed to be drilled out. Bear this in mind if you try to remove the cover with the pump in-situ => you could make more work for yourself if like mine the screws are corroded into place. I think it is easier to drill out screws on the cover of the pump with the pump removed.

Most probably, it's all one-in-the same issue. The check valve bits block the pump intake. A very common occurence.

If three pieces (spring, plunger and retainer plate) can be retrieved with the pump in place, there should be no need to remove and/or further disassemble the pump.