I thought about adding one of the Ford pumps as well. When I was desgining my serpentine belt drive I was using different scenarios to route the belt. I would have made a block off plate for the old pump and use that spot as a mount for the new pump so I could get more wrap on the pulleys. So far I do not have a need to change the initial desgin, but down the road...maybe some changes are due.

From what I've seen, the sprocket that drives the injection pump has a cam lobe on the face of it that contacts to follower on the vacuum pump. All around this area is open into the timing cover, and the the vacuum pump vents into the timing cover as well, so it's all open on the engine side like a gasser fuel pump. When things fail the debris gets shot right into the timing cover, and caught by the timing chain.

When the Vacuum-pump failed on my '84 TD, I thought about looking for an alternative belt-driven pump at the Virginia Beach Pick-N-Pull. But the day I went was so miserably hot & tropical, I thought I was going to pass out just pulling an OE pump off a decrepit '81 240D. Anyway I didn't have the resources there to retrofit a belt-pump.
And the 240D pump wound up being only temporary after all, as I didn't feel comfortable making the 200-mile return trip to Alexandia worrying about the possibility of 12 more ball bearings dropping into my timing chain. So I found & installed a new pump.
Next trip to Virginia Beach, I'll check out some US vehicles at the Pick-N-Pull for possible retrofit vacuum-pump candidates.


Happy Motoring, Mark

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DrDKW

So the vacuume pump is cam driven. If I want to eliminate it and use an electric one, is it as simple as removing it and installing a cover?

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

There is no reason to change the design if you are willing to install a correct new pump.

Within the last 3 months there was a tread on changing only the Bearing on the Drive Arm.

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84 300D, 82 Volvo 244Gl Diesel

Remove the lever arm from an old pump and use the pump case as a cover. You might reseal the front cover of the pump so it doesn't loosen, leak and rattle.

Sixto
87 300D

I just carry a spare stock one with me in the trunk and the right allen wrench, i dont know the warning sounds they make when they go out but Ill keep my fingers crossed.

Front what I understand, the warning noise is a bang, and the engine stops.
I'm just trying to make it so when I'm a few hours from civilization on a trail somewhere, I don't have to worry about terminal failures.
I know that replacement parts are available, but the way things are made now, I just don't trust that style setup. Besides, who says the most complex system is the best? Often, it's the simplest one that lasts the longest. A lot of things Mercedes did really stacked the deck against the engine, but then I really doubt they intended these things to rack up as many miles as they do.

I had no warning with my vacuum-pump until I hit the brakes at the Virginia Beach - Laskin Road exit. If there was any odd noise, I didn't hear it at freeway speed.

I think the point is that it may be wise to deal with an old pump BEFORE it's failure damages the timng chain & gears. I was very lucky that the bearings didn't cause any apparent damage to my engine. I'm no longer worried about retrofitting my TD, since it now has a new pump, that will hopefully outlast the car.
Several years ago, a friend bought an '85 190D, with nearly 400K miles, at an auction, with the old vacuum pump laying in the trunk. The loose bearings had also made their way to that car's oil-pan without causing any damage.

It might be interesting to take a poll here, of others that have experienced vacuum-pump failure, and see how many were lucky, or not!

Happy Motoring, Mark

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DrDKW

Does the electric vac pumps in the later W124's & C series for the central locking have enough capacity to work the brake booster? I have never tried it.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Not even close. Not rated for continuous duty, either.

Sixto
87 300D

Here's a pic of the vacuum pump. What about designing and installing a screen of some sort to contain the debri avoiding mayhem when it lets go?

How is the vac pump lubricated?

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

You can't put a screen because the lever has to roll on the IP timer sprocket.

Sixto
87 300D

What about a screen with an opening just big enough for the lever?

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked