can U replace diaphram w/o removing pump
 

can you replace the vacuum pump diaphram without removing the whole pump?
I have a 79 300sd. Attached is a pic of the pump as viewed from above. Is the diaphram under this top bolted on section or is it deeper in the mix?

I believe that is a piston type pump, not a diaphram pump. Is it pumping oil into the intake or does it fail to produce vac?

Peter

Doesn't appear to be oil going to the intake. The tube from the pump to the intake is a pretty fair size diameter and is a clear color. It doesn't appear to have oil coating the inside. There is oil goop all around where it connects under the air filter but that could be from any number of other spots. There has been oil in the past in the smaller diameter line going back to the cutoff, brake boost, and such.
Pretty confident that it does have a diaphragm cuz the prior owner said that the one that is in there is of his own making.

I just had some other work done by a mechanic and he for free for his own curiousity did a "smoke test" on my vacuum system. He said that he didn't see any leaks in the connections but that the pump was putting out very little pressure.

Sometimes when the car won't turn off correctly it will turn off after you rev the engine a bit. (suggesting weak pressure, right?)

If the pump is generating very little vacuum, you will have difficulty shutting down,
 

Hello angst
If the pump is generating very little vacuum, you will have difficulty shutting down, shifting and climate control problems.
Repair ASAP.
Have a great day.

angst


Mine is the diaphragm type but check valves, I assume are common to both type pumps, Check your check valves, that was the problem with mine, One leaked back so I replaced both. The diaphragm looked fine so I left it.

That comes from a leaking diaphram in the vacuum shutoff device on the injection pump. And you say it shuts down slowly. Hmm, could be a connection here. ;)