Hi, I have a '79 300D that has no vacuum at the pump. The vacuum line system holds a vacuum when using a mity vac pump, but the engine vac pump doesn't generate any more vacuum when the engine is running.

The pump that I have is the diaphram type. I appreciate very much the various photo attachments that I found using the Search.

I removed all 8 of the screws that attach the valve housing flange to the pump housing. However, I can't budge the valve housing with reasonable force. My question is: Is there anything connecting the valve housing to the pump housing besides the 8 screws (that I already removed)? Does the valve housing just come off by pulling it forward towards the radiator?

Maybe the valve housing is just baked onto the diaphram.

Any ideas on how to dislodge the front part of the diaphram vacuum pump would be greatly appreciated.

GW

I removed the whole vacuum pump to see why the pump housing wasn't separating at the housing. I was amazed to find that the roller, bearings and roller shaft of the pump internals are missing. I guess something busted apart and the parts fell nicely out of the timing chain's way into the oil pan.

I read a recent thread about this same disaster. I guess it's not that common because there aren't many more threads about it. The sypmtoms are a metalic "ticking" sound for maybe a thousand miles. Not real loud, but definitely metalic.

The circular cam isn't chewed up at all so a used pump should be the fix.

I wonder if it is worth getting the busted parts out of the oilpan or leaving them there. Any ideas?

I would not worry about it.... you have a screen.. protecting the intake of the oil pump...