Any advice for rebuilding a vacuum pump?

[rfdillon]

Folks, about every other month, for a few days at a time, I will lose most of my vacuum, causing the brakes to be very hard, and causing me to sometimes have to open the hood to turn off the engine. I have sealed off the driver's compartment from the vacuum system, so it is not a leak in the doors. I have been told that there are some valves in the vacuum pump that are not working correctly, and that is causing the problem. My question is this:
How much of a hassle is it to rebuild or replace the vacuum pump? It is my understanding that I will need to remove the radiator, and that perhaps a kit exists that would allow me to rebuild the vacuum pump. Does anyone else have any experience with this, and is it a relatively easy and straightforward task? Thanks so much in advance!

[tangofox007]

Originally Posted by rfdillon

Folks, about every other month, for a few days at a time, I will lose most of my vacuum

The pump itself is probably fine. There is a check valve in the nipple where the hard line attaches to the pump. The check valve tends to break. When that happens, the loose components intermittently block air flow into the vacuum pump.

You can remove the nipple while the pump is still in place. I would suggest that be your first step. You will probably find that the check valve components have dropped into the pump inlet.

[pselaphid]

I concur, tangofox told me that and despite my skepticism, was quite correct. Not sure I could have extracted the little valve parts but they are probably blocking the intake valve and you might be able to fish them out. I rebuilt mine because I had a kit on hand. It wasn't difficult, but you have to build a little stand and follow the DYI instructions.

[pselaphid]

Just sent you an email with links to some pics.

[jbaj007]

You don't say which car, but the intermittent nature of it tells me the odds are you just need to buy this part:

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=26W03483526W034VKV&year=1983&make=MB&model=300-DT-001&category=All&part=Vacuum+Pump+Check+Valve

[rfdillon]

Pselaphid and all others:
Thanks so much for your advice and replies!

Do these check valves just thread into the body of the vacuum pump, and thus theoretically I could loosen the vacuum line, then unbolt the check valve and replace it without messing with the vacuum pump?

The pictures that Pselaphid sent me make the rebuild job look a little daunting! Thanks again for your help