My turbo 240D had a great vacuum system before and just after the turbo engine swap. I could unlock the doors using the vacuum assist after letting the car sit for two weeks. During the car’s 350-mile maiden voyage it began to have difficulty shutting off and locking, however the brake boost still seemed to work. I verified that the fuel cut-off valve was working using mouth suction, then tried blocking off the only other vacuum system…the door locks. Now I can at least shut off the car. Before plugging the lock system I put first my finger, then my lip to the open vacuum line and was only able to detect a very small suction. Does this sound like the vacuum pump needs to be rebuilt? I will buy a vacuum test tool tomorrow and post back with any leaks I find as well as the amount of suction the vacuum pump is pulling. Thanks in advance for the advice. -Bryan

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

The vaccum diaphragm may have torn. Even being torn it will produce some vaccum but not much.

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1974 240D 3.0L 4(M) - 250K -OM617.910 + 300D FW + Rajay turbo power!
1977 6.9 3(A) - 84k

Did the donor 617 sit for a while before you installed it in the 240? Possable that the vac pump on the 617 was ready to go or thr diaphram got hard from sitting. Your 240 like my '77 240 use those 4 diaphram door lock pods. If one of the four leak then..... you know what happens. Mine are leaking on my car yet my power brakes work wonderfull.

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My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.

The engine did sit in the donor car for an unknown amount of time before being used in this car. Which rebuild kit will I need? Fastlane shows several Here

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

If the vac pump has two lines, it is the diaphragm (old style) pump. If it has a single line it is the piston type. I believe that both types need two separate kits to completely rebuild. I recently did my diaphram type, I only replaced the diaphragm because the pump seemed to be working alright, but oil was getting into the vacuum tubes.

Vacuum pump diaphragm replacement pix

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Sonny


86 190D N/A 2.5L Auto 265k "Ruby" -Sold-
79 300D 242k "Condi" my first -sold- RIP
2013 chevy sonic hatchback - had to for work

It is the new style, 1 hose type (Using the older style brake booster hose. One of many things that gives it the name MacGyver )

No harm driving it in this state correct? I read some horror threads about exploding pumps.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1U41BUPZR1WJ0459OD&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1980&product=D3010-11793&application=000021765

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1U41BUPZR1WJ0459OD&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1980&product=D3010-11794&application=000021772

Don't know about drive ability.

http://diymbrepair.com/easley/Rebuild_vac_pump.htm

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Sonny


86 190D N/A 2.5L Auto 265k "Ruby" -Sold-
79 300D 242k "Condi" my first -sold- RIP
2013 chevy sonic hatchback - had to for work