Change those w124, 606 engined vacuum pumps before 250k miles

[engatwork]

Here is a shot of the old and new vacuum pump from a 1995 E300 with 243k miles on it. The bearing on the old vacuum pump is actually kinda hard to turn. My suggestion is to change them out before you get to 250k miles to protect that engine.

[Bio300TDTdriver]

Originally Posted by engatwork

Here is a shot of the old and new vacuum pump from a 1995 E300 with 243k miles on it. The bearing on the old vacuum pump is actually kinda hard to turn. My suggestion is to change them out before you get to 250k miles to protect that engine.

I would even say 200,000 to be safe. That's when I did mine.

[lietuviai]

Those clever engineers at Mercedes Benz! They figured out how to put all kinds of time bombs in their engines in the later years.

[Fulcrum525]

Same thing goes for the 603 vacuum pump.... and I think the 190d's as well.....

[JonL]

Yes, 190D as well.

[WINGAS]

Funny, mine just started making a horrendous noise, thankfully within minutes of my house. Just called Phil for the new one. 259K miles.

Any trick to R&R this bad boy?

[04 Diesel]

Originally Posted by WINGAS

Funny, mine just started making a horrendous noise, thankfully within minutes of my house. Just called Phil for the new one. 259K miles.

Any trick to R&R this bad boy?

How much for a new one?

[WINGAS]

$356.

[Jeremy5848]

Originally Posted by WINGAS

Funny, mine just started making a horrendous noise, thankfully within minutes of my house. Just called Phil for the new one. 259K miles.

Any trick to R&R this bad boy?

Only thing I can think of is to back off the bolts holding the vacuum pump to the timing cover slowly and gradually because the spring in the pump is under pressure from the cam that drives it. There's a position in which this pressure is minimized; I can't remember if it's TDC or something else but someone will know or point us to a past thread. With the pump off, you can see the cam and can rotate the engine to minimize pressure on the new pump. If you work really hard at doing it wrong you can crack the new pump.

There is a choice of gaskets and one kind interferes with the timing chain basket. The basket must be removed to use the "pocket" gasket. The pocket gasket traps some oil so the pump doesn't start dry when you start the engine. The timing chain basket is useful when working on the timing chain or the IP but doesn't need to be in the engine all the time. Just don't throw it away. Many threads on this subject in this forum.

You probably will want to remove the fan and serpentine belt but this is a matter of opinion; there are those who claim they can change a vacuum pump without even opening the hood but I think they exaggerate.

Jeremy

[dieseldiehard]

I recall its TDC where the timing ramp is away from the vac pump actuator arm. I do recall throwing out the basket though when I did the job once. Its a little tricky though, you want to read through the job description twice before jumping in and loosening the bolts.
You can change the 603 vac pump with the radiator in place but the fan and shroud needs to be removed, as well as the upper rad hose.
gsxr has started a couple of very comprehensive threads on this subject and should be studied before attempting the job:
http://www.peachparts.com/shopforum/diesel-discussion/231260-om603-vacuum-pump-explosion-bearing-intact-injection-pump-timing-device-wrecked.html#post1946902
OM603: Vacuum pump explosion, bearing intact! Injection Pump Timing device wrecked
My advise has always bee if your vac pump has no bolts holding the cover on (crimped over around the edges) get rid of it ASAP.

My story: A nice man who had been having his SDL serviced where I worked part time gave the car to his daughter for her wedding present. She and her new husband used it for their honeymoon. Unfortunately they had the car towed in less than 2 months later saying the engine stopped. Well, it had a hole in the side of the block where a rod blew out after the timing chain broke, all because of THE VACUUM PUMP! He said the car had been making a ticking noise but they didn't think it was serious enough to merit sending it to the shop right away. Lesson learned.

I learned how bad these things are when, in about 1990 I saw an SDL having a vac pump replaced with less than 100K miles on the speedo with all the little bearings falling out of it into the engine, it was a big job to clean it out. This part is clearly not one of MB's best parts specifications. There are even reports of the improved style (with the Torx bolts on the cover) failing prematurely. Its definitely the achilles heel of the later 6 cyl diesel engines

[longshore1]

I don't like the sound of that, I don't know if the pump was changed before I bought the car. any symptoms of a worm pump I should know.

[sasquatchgeoff]

Originally Posted by dieseldiehard

I recall its TDC where the timing ramp is away from the vac pump actuator arm. I do recall throwing out the basket though when I did the job once. <>
My advise has always bee if your vac pump has no bolts holding the cover on (crimped over around the edges) get rid of it ASAP.

My story: A nice man who had been having his SDL serviced where I worked part time gave the car to his daughter for her wedding present. She and her new husband used it for their honeymoon. Unfortunately they had the car towed in less than 2 months later saying the engine stopped. Well, it had a hole in the side of the block where a rod blew out after the timing chain broke, all because of THE VACUUM PUMP! He said the car had been making a ticking noise but they didn't think it was serious enough to merit sending it to the shop right away. Lesson learned.

I learned how bad these things are when, in about 1990 I saw an SDL having a vac pump replaced with less than 100K miles on the speedo with all the little bearings falling out of it into the engine, it was a big job to clean it out. This part is clearly not one of MB's best parts specifications. There are even reports of the improved style (with the Torx bolts on the cover) failing prematurely. Its definitely the achilles heel of the later 6 cyl diesel engines

On my 602, TDC puts the cam lobe at the highest position against the pump bearing and spring, i.e. practically impossible to install w/o cracking the pump casting. 1/4 turn of the timer puts the dip in the cam in position to receive the pump bearing more safely. EDIT: From FSM 43-618

"4. Fasten vacuum pump with a new gasket to
crankcase. Make sure that the lift curve of drive
flange is at BDC."

My working pump is the one with the torx screws on the cover, but the bearing cartridge is the open style, so I am planning on replacing it since I have replaced practically everything else in the top end of the engine. The pumps are pricey insurance.

[curlytom]

Originally Posted by longshore1

any symptoms of a worm pump I should know.

Anyone? My car has started with a rattle noise at the front of the engine which I've attributed to a worn belt tension damper, but after reading this thread, maybe I'm wrong?

[sasquatchgeoff]

Belt tensioner pins get loose - mine did - in spite of the 90nm torque spec. It is a 12mm hex socket. When I dismantled my engine I found mine loose enough to turn out by hand...

One way to check the VP is to take it off to check the bearing, albeit very carefully. I would suggest turning out each bolt one turn at a time, going around until all are slowly backed out - otherwise the ears in the casting that contain the bolt holes will crack - especially those around the upper & right part of the pump - where the spring is.

[Chris W.]

It self destructed about 3 weeks ago. Unfortunately when it failed, it took out the timing device. A fairly simple DIY repair then became something I decided to have my indy do. I was able to take off the old pump without removing the fan, by the way. Took off the fan shroud, released the tensioner, and I had room to get all the bolts out of the vac pump.

Initial symptoms were, by the way, lack of vacuum as evidenced by hard brakes, show shutdown, and dash pods not acting right. If I had changed it right away, I probably would have been ok. Stupidly I drove it for a week or so longer, (it seemed to work ok at higher rpm) until very loud banging was heard, just as I arrived home one night.

So, I concur that when your 606 reaches 250K, change the pump as a preventative measure.

BTW Curly, my guess is in fact the belt tensioner damper. If the rattle goes away when you increase idle speed a tad, that is most likely it. And it is possible to change this without removing the pulley in the way, just carefully loosen the pulley bit by bit as you remove the lower damper bolt and you'll get the damper bolt out before the pulley bolts come out.

Rgds,
Chris W.
'95 E300D, 290K