I received my new vacuum pump in the mail and I have done my homework on how to install it on my Mercedes. Only problem is that I am unable to figure out what the torque specs for the vacuum pump actually is. Does anyone know?

Car in question is 86 300 SDL

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1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

You may be able to find them online or may need to pick up a workshop manual. The workshop manual will have all the torque specs and wiring diagrams for a variety of projects. I have attached a link below if you're interested. Please let us know if you have any questions!
Mercedes-Benz S-Class (1981-1991) W126 - Books & Technical Documentation - Page 1

Interestingly the FSM doesn't seem to give a torque spec for the attachment bolts. Not that you could really get a torque wrench down in there anyway without removing the radiator and drive belt. When I did mine, I did it by feel. "Snug and then some". Use a new gasket and it shouldn't leak.

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Additionally, before getting carried away, check your roller-coaster cam and make sure it isn't grooved or flattened before you replace the pump. If it shows signs of wear, replace it. Pierburg warns of denying warranty due to pump failure caused by a worn face cam.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Should I look around some junk yards for a replacement IF I find that the stroke curve is worn?

Pierburg states that the part ins't sold as an individual part anymore and the entire "injection adjustment device" will have to replaced...and I can't find any places that sell such a device.

Man, if it is worn or damaged, then this is gonna suck .

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

I may have to heavily consider investing into a couple of the books in there. Could probably save me the time from digging in multiple threads on the forums just to find the most nit picking details about a project.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Shell out the $10 or so on ePrey for a set of FSM CD's for the W126, or join the Startek site for an online copy of the W126 FSM.

The rollercoaster cam is probably fine if the existing vacuum pump is still sound and the engine doesn't have a bajillion miles on it. The one in my SDL was and is fine. The factory vacuum pump was still fine too, but at 200K+ miles, I wasn't going to see how long it lasted. If it does have wear or needs replaced, they're not hard to find. They're all over ePrey, and if you ask nicely in the Wanted/For-Sale section of this forum you can probably get one for a song.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

No Vacuum Pump Bolt (Torque)Specs Provided for OM 601,602 or 603

I've searched the FSM discs till my eyes were hanging out of my head.

If y'all find them shoot me a link please!

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'84 300SD sold
124.128

From foggy memory, 25 Nm. The appropriate year Technical Data Manual should have them.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

I did what the OP suggested. Snug then a bit more. Keep in mind that your threading into softer metal.


It is important to:

1. Rotate the motor so that the timing cam connected to the IP is positioned so that the lobe is at a low spot in reference to the vacuum pump cam follower.
2. Secure the vacuum pump bolts in a cross pattern (x2). Example all bolts are initially tightened in cross pattern to about 50% snug. Then continue in cross fashion again to final torque. 25nm sounds about correct.

Make sure there are no surface nicks, prior gasket film, etc. prior to bolt up.


A light spray of Permatex 99GA High Tack Spray-A-Gasket Sealant available at your local auto store onto both sides of the gasket prior to assembly will help keep things in place as you bolt up. Let the tack set up for a few minutes prior to install.

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1986 300SDL 440,xxx

Oh, okay thank you.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

How do I check to see if the lobe is at a low spot with respect to the vacuum pump cam follower? Do I set the engine to TDC?
And a cross pattern means to screw in the bolts at midway height, horizontally correct?

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

In my copy of the Technical Data Book 1987 edition, no torque spec was listed. I wrote a note to myself to use 12 Nm. I suspect that the origin of 12 Nm is from generic torque recommendations for that particular size bolt thread into aluminum, which I must have hunted down at one point.

I've also got a copy of the 126 FSM procedure 43-0618, R&R of the vacuum pump, and it does NOT list any spec either.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC