It started out with a knocking noise coming from drivers side engine compartment in the front. I took off the power steering belt, started it and it still made the noise. This led me to believe their was a problem with the vacuum pump. I pulled out the vacuum pump and noticed the bearing was dirty and kind of hard to turn. The bearing was also seemed to be worn and some of the balls in the bearing were shot. I then looked at the wavy plate that is the drive mechenism for the pump. I saw that the wavy plate had a line that was worn a little bit and also noticed some metal shavings as if the bearing was not spinning and was wearing on that wavy plate. Just wanted to make sure this is where the noise I heard was coming from. Also was wondering what should be replaced to repair this(new bearing, gaskets, diaghram, etc). And wanted to know what steps should be taken to take apart the vacuum pump repair it and put it back together and reinstall the pump in the car.

Thanks, Dan 1980 240d, 208k

Dan is the new owner of his Grandfather's 1980 240D, which has been sitting in a garage for a while. His Grandfather has reached the age where driving is no longer a good idea, so the best choice for finding a new home was to pass it on to a young man just starting out his driving experience. You guys have helped with this vehicle a few times in the past, and will undoubtedly be asked to help the new owner keep this car running for another lifetime.

Basically the noise was uncovered by Dan and his father, and confirmed by son Peter (the Grandfather is my father in law), as unusual. I heard it last weekend and we did some research here and were led to suspect the vacuum pump. Dan had selectively removed other running stuff in the vicinity and the clanking noise did not subside. This seems to be a sign of vacuum pump impending failure. So, Dan and his father removed the vacuum pump and we inspected it today. The bearing, completely unloaded is very rough with widely varying torque required to turn it, much like there is particulate between the bearing races and balls. Careful visual examination of the swashplate or whatever the wavy drive plate is called, shows fine metallic particulate around it along with a very prominent wear line.

We want to rebuild the pump so we were hoping someone has done this and can offer some idea of what to expect when the front cover is removed. We are looking to replace the diaphragm and possibly the reed valves and the rocker arm assembly. The spring behind the rocker arm assembly seems very stiff - we can't budge it when we try to press it in. Thsi leads me to believe we should expect a significant spring force when we open the front mechanical joint, and we will have to compress this spring at some point when we put the assembly back together. Any hints? Thanks, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I've replaced the diaphragm and check valves on the front. It's a quick and easy repair. I have not done the rest. Someone posted here recently about doing his and having to create a jig of some kind to compress the spring for reinstallation (I think).

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Is this a diaphram type or piston type? I'm not sure about 1980. There is a pictorial for the piston type in the DIY section. When I rebuilt my diaphragm type I did not have to do any bearings etc. It was not making noise, just leaking oil.

edit: Diaphragm type will have two vac lines attatched to the front of the pump, piston type will have only one.

__________________
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

That would be the injection timer. Removal and installation is not a basic DIY job.

The timing chain goes around that injection timer or "timing device" so it is a fairly big project too replace it.

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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"

Guys,

This is a diaphragm vacuum pump with the two lines coming in the top. The swashplate is the thing that pushes the diaphragm out and the spring pushes it back in, with the valves on the "air" side of the diaphragm turning that into pumping action.

The interface between the swashplate, which I do not think needs to be replaced or repaired, and the OD race of the bearing that forms the contact surface of the rocker arm like device that pushes a rod that is connected to the diaphragm shows signs of wear, but the problem is in the little rolling element bearing. It doesn't roll smoothly anymore.

So, replacing that thing means the spring will come out. Right now I can't push hard enough with my fingers to deflect the spring at all, so I am concerned about how Dan will get the unit back together. Any help on how that is accomplished would be gratefully welcomed. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

OK, like I say I've never done that , however in the piston type rebuild pictorial it says to build a jig. And mount the pump on it. Well here, take a look at the link. See if there is anything there that might help you.



http://web.archive.org/web/20050306142927/business.baylor.edu/Richard_Easley/autofaqs/Vacuum+Pump/Rebuild_vac_pump.htm

__________________
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