W116, BENZ AID - COMMON QUESTIONS AND ANSWERS

1979 300TD transmission vacuum controls???

Hi all,

I've got a 1979 300TD non-turbo that isn't shifting correctly. I'd like to start out with the vaccum system, but can't seem to come up with a schematic.

I've got Kent's transmission tuning manual, but the transmission in the 1979 wagon looks to be different than any of those explicitly described in the manual, and the vacuum schematics in the appendix don't seem to match either.

I've got two questions:

What is (and how do I test) the item labeled "B" in this picture? (I assume it's the VCV)

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

86 300D run-away engine

I have a 1986 124 300sd. I was changing out the glow plugs with the glow plug reamer kit available at MercedesSource, Awesome kit everything was a breeze lots of carbon build up. The problem arose on the test drive when the car accelerated uncontrollably! Upon close inspection I noticed that two hard fuel lines had been replaced, (by the previous owner) and in working the throttle linkage noted that ever so often the linkage rubbed on the fuel lines causing the throttle to stick in the open position.

Chassis Model Number

W124

Forums

Diesel Engine Specific Aid

1981 300TD-T Lack of Power

This 300TD-T has been running on Veg for about 3 years and 12k miles, I have owned it about 5 months. The rebuilt engine has 50k miles in it. Starting two weeks ago, the wife noticed a subtle power loss on hills and more white smoke than usual (this car has burned very clean except at start up). I drove the car last week, and tested it on a few residential hills in the neighborhood. At idle, the engine revs well…on the flats power is OK, but definitely not as strong as a few weeks ago… going up steep hills is impossible.

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

1975 300D Door Locks Repair

This weekend I repaired 2 doors using the rubber diaphragm kit from this website. However; on the front passenger door the pull/push knob stem seems to be dis-connected from the rod that is controlled by the actuator to lock and unlock door. Not sure what I need to repair, hard to see.

Also, I'm looking for the driver side door lock switch actuator that has the 3 vacuum lines, 1 in and 2 out but can't locate on this site.

Chassis Model Number

W115

Forums

Body and Interior Specific Aid

1981 300TD-T "Switch Over Valve" disconnected

In doing some routine maintenance on our recently acquired 300TD-T I came across what has been called the "switch over valve" attached to the fire wall, next to brake booster. Both the vacuum line from the turbo and the alda have been disconnected and a short piece of hose connects the two.... a bypass. I understand that this can damage the engine. Is there any test to see if this valve still works before I reassemble the correct way?

Thanks is advance.

Steve

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

'91 350SD Differential Mount

I just replaced my differential mount. Yes, it fixed the rear sag problem!! One of the 4 13mm bolts that hold it into position on the subframe snapped off inside the subframe while removing the old mount. Is there a way to get that piece out of the hollow subframe member so I can replace the bolt (assuming the threaded insert is ok...I suspect it may be rusted, thus the break)? Are bolts 3 enough to hold the mount in place?

Chassis Model Number

W126

Forums

Transmission / Suspension Specific Aid

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