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?

Attached Thumbnails

 

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

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

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?)

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.

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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.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

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.

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Rick Miley
2014 Tesla Model S
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Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
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