Excellent post Beagle. If you do decide to leave you will be missed!

This is incredibly timely for me, and a bit sad. Even though I don't know you Beagle, it is a loss, and I thank you for this and the other info you have shared.

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1985 300D-189k The 'UD', Ivory and Pinkamino
1979 300D-211k Dark Gray, Parchment
A 1980 Harley-~166k and
A 1994 Ford diesel pickup-349k and
A 1990 gasser Volvo wagon-145k

Any maintenance to be done on those?

Email me if there is, as I probably will not get back to check this thread.

NO.

The later 60x vacuum pumps where superseded many times due to failure issues.

There are NO repair kits for any of them.

the current valid part number is:
Vacuum Pump
MB# 000 230 31 65

.

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ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/

I have heard and read on several occasions that a particular sound is associated with a failing vaccuum pump? What is this sound? And when/if is it most audible -- low RPMs, high RPMs, etc?

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1983 300CDT -- 177K

Theres more than one way they can fail and I'm sure the one I had experience with must have made noise for a while. I bought this running 240D but it got trashed when something started a fire under the dash. I pulled the vacuum pump just to check it and discovered the piston had broken through (later pump) the housing and that was due to a warn bushing that lives in back of the timing device. That warn bushing allowed the timing device to slam back and forth on the shaft hitting the engine block on one side and the vacuum pump on the other side. There was a deep grove in the block so that must have made some noise. I measured 2.5mm of slop that that timing device had to move. Thats what took out this one, I captured all the shrapnel before it did any harm. So I always check the end play of the timing device when the pump is off.

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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"

New Vacuum Pump Ruined due to too much Timer/Intermediate Shaft End Play (the title from my notes).
http://www.peachparts.com/shopforum/showthread.php?t=258062&highlight=vacuum

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84 300D, 82 Volvo 244Gl Diesel

Thanks for the positive responses Guys.

Steve

I believe that the root cause of almost all of these pump failures is a leaking vacuum system that results in continuous full stroke operation of the pump at high rpm. It is unfair to blame the play in the timing device assembly for taking out the pump when it is the pump that was responsible for destroying the intermediate shaft bushing in the first place. The intermediate shaft has negligible thrust of its own account.

It is probably easier to explain what I’m getting at by comparing the two separate scenarios of driving with or without a vacuum leak. Let’s look at a 200-mile journey first with no leaks:

1)You start up and after 15 sec at idle 25” is reached (FSM) and the pump then parks itself with the roller just kissing the cams. It stays that way as you drive off until you use you your brakes, then the roller dips into the cam a little way for no more than 10 sec to top up and then parks again. This continues throughout the journey. It would probably be an exaggeration to say the pump had been working for a total of 10 min of that 3-hour journey and non of it at full stroke. Both the pump and the timer have been having a very easy time of it.

A very different picture with leaks:

2)At start up the pump will never reach >25” and continues to pump at full stroke until the engine is turned off - it never parks. The level of vacuum reached will depend on the severity of the leak but it will give reduced brake assist. The real damage occurs at high rpm and full stroke for extended periods. It takes 57kg to compress the rocker to a full stroke and at high rpm the cam is thrashing the S#&T out of the rocker and those little 626 bearings while at the same time hammering the F/P shaft thrust bearing. This will continue uninterrupted for the full 3-hour journey! I leave the consequences to your imagination.

For Army...
Pump Piston Replacement

Vac Pump Removal
Qwerty
You will need to go to a specialist bearing store and get them to order two 6 ball open "precision" 626 for you. The 8 and 6 ball non-precision bearings are very common so be careful and make sure it is a top quality brand. Check their catalog.

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Beagle

Beagle, Well I wont to be the first to admit that I had never considered that. That burned up car that I got, I have an idea the vacuum system was not maintained by other things I found.

I just inspected a "spare" diaphragm pump I had and I discovered It has a round, 12mm hole (with the piece right there) right above where the head of the center bolt for the diaphragm comes up. Theres a round indentation in the casting for that bolt head and it looked like it went a little to far. On the other side is the chamber with the two checks, the holes right between them Like I said, it was a spare. Thanks for the good info.

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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"

If that is the case, it would take that much pressure differential to prevent the spring from returning the piston, would it not? Even with near-perfect vacuum, that would require a piston surface area in excess of 8 square inches. With a more realistic pressure differential, the required piston size would increase by around 50%.

I bet the spring when collapsed has a hold mechanism of some sort.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

If you are on the Freeway with the A/C on and the Radio on you are not likely to hear your Vacuum Pump.
If it is going to make noise you will most likely hear it at low speeds.

If you read the accounts the Vacuum Pump often fails right at start up or after that Car has just started down the Road good. In those cases there was a only a brief period of noise.

Others have had the Vacuum Pump make sort of a chinking sound; but not real loud before it failed.

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84 300D, 82 Volvo 244Gl Diesel

Is there a way to tell if the vacuum pump is working all the time? Does it make a sound as it is working properly?

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cbjukraine
'84 300D

Not stock, you'd have to ad in a vacuum gauge, and see what it's putting out.
if vacuum things are not working, it's running all the time.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

so what about the VCV on the IP? It bleeds vacuum every time the transmission shifts, no? wouldn't this mean the pump is running to replace the bled off vacuum when the transmission shifts?

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cbjukraine
'84 300D