W124 vacuum pump

[oliviersp1]

Hi,
I have a problem with my 300D Turbo (93) 527,000kms
It seems that the vacuum pump (at front of the engine) is out of service
i cannot brake (hard pedal) or stop the engine (stop ok with manual leverage), and no vacuum pressure in the hoses...
I'm wondering how to repair it, i saw 4 torx screws on the front, but i don't know if this is enough to service it
i'm searching for an exploded view but i can't find it in the manuals
can someone help me please ?
Thanks

 

[Seamster15]

You need ... Diesel Man!

 

[bolide]

Are you sure the pump has failed? It may be that you just have a vacuum leak

I would think it unlikely that you could repair a failed pump as the tolerances would be very fine. I'd just replace it

Nick Froome
www.w124.co.uk

 

[oliviersp1]

hum no i don't think it can be a vacuum leak, i disconnect the neraest hose and there is no vacuum pressure...
even with a leak, there would be vacuum pressure i think ?

 

[Number_Cruncher]

I don't *think* that a vacuum pump which is so modern can be repaired - replacement only. Some of the vacuum pumps on the W123 diesels could be repaired.

But, the main thing to be wary of is that some kinds of vacuum pump failure result in fragments of vacuum pump becoming tangled up in the timing chain. If the chain goes, your engine's had it!

Don't continure to run the car until you're sure the chain isn't about to be damaged by bits of pump. If the pump is damaged on the chain side, then, as well as sorting the vacuum pump, it is probably worth turning the engine over slowly, watching the chain for damage along its entire length.

 

[compress ignite]

Not ReBuilable (Pierburg doesn't release parts!)

GSXR recently had a Vacuum Pump catastrophe on his OM603 powered W124.

Link:http://mercedesshop.com/shopforum/showthread.php?t=231260

He didn't lose the engine...'Heard the noise and investigated.

As advised, Do Not Run That Engine Until you Replace the Vacuum Pump!

 

[oliviersp1]

Hi,
oups that's pretty bad !
there's no special noise at all in may case so i wish there is no dammage inside, i will unmount it and see...
Do you know if i need to remove the radiator ?
Thanks

 

[Number_Cruncher]

>>Do you know if i need to remove the radiator ?

I think the radiator should be able to stay in place (it did when I removed mine on my OM606), but, you'll probably need to remove the cowling.

 

[oliviersp1]

i unmounted it, radiator stay in place w/o problem, just the cowling around the fan as you said
and the result is........bad !

here are the pictures
http://picasaweb.google.com/oliviersp1/Mercedes_300D_turbo

it's more than out of service...
don't know where are the balls of the bearings...
the only positive point, it seems that the sprocket is not that bad, i cannot see any "anormal" marks
what is amazing is that it doesn't made any suspect noise !!!

i let you watch the pictures and tell me what you think about that

 

[Number_Cruncher]

Well, clearly, you need a new vac pump!

If this were my engine, I would also remove the cam cover and the sump, and I would clean out all the debris in there, and I would turn the engine over with a socket on the crank bolt, the entire length of the timing chain, the oil pump chain, and all of the teeth of all of the chainwheels for any damage.

If there is no damage at all, then, I would say you have been lucky - although it might not feel like it at the moment!

By looking up and down through the timing chain cavity, you should be able to check that none of the balls or other debris is lodged anywhere in there.

I can't see from the piccies if the face cam on the nose of the injector pump chainwheel is OK - it's probably acceptable to dress any small impact marks and burrs off there with a file and emery cloth (taking care to catch the filings!)

 

[oliviersp1]

pump ordered
i will try to turn the engine to check the chain and sprocket as you said
removing the sump would be a great idea, to catch the bearing's balls
i will take a look at the manual to see how to do it
the face cam on the nose of the injector pump chainwheel seems to be ok, just "normal" wear i think, this is what i don't understand, where can have the pump touch to erode like that without a mark on the chainwheel
strange...

Thanks

 

[Dieselman]

The balls are probably rolling around in the sump as they should just fall down infront of th echain, but may have passes by it.
I wouldn't do anything to the cam plate as it will be a case hardened finish so any filing will damage it. It looks Ok anyway.

The balls may come out with an oil change and poke around with a magnetic pickup tool.

 

[Number_Cruncher]

>>I wouldn't do anything to the cam plate as it will be a case hardened finish so any filing will damage it.

I was thinking of burrs and other impact damage possibly caused by the failing vac pump which would make the roller on the new vac pump jump, or jolt. If the surface is already damaged locally, a little further local "damage" by filing and sanding to make it smooth again can't hurt. Of course, if it's not broken - don't fix it!

 

[Dieselman]

Of course if it is damaged then a little fettling would be good, but looking at the pictures suggests it is alright.
Looking closely you can see the damage to the roller carrier is from contacting the raised lobes and not from dragging round the ring.

 

[Number_Cruncher]

Yes, as I mentioned above, I can't really tell from the pictures that the cam is OK - there's a lot of reflection, and it's difficult to see exactly what the surface is really like.

You're probably right, and there probably is no damage, but, I would suggest that the OP has a good look, and feel of the surface, to make sure it's OK. It'll only take 5 minutes, and will cost nowt.

 

[oliviersp1]

Hi,
I catched 11 balls by removing just the bolt of the sump, with a magnetic tool...
it means that one (or more) are still in the sump or elsewhere... with the ball's bracket too !
can you tell me what is that part on the right of the sump ?
http://picasaweb.google.com/oliviersp1/Mercedes_300D_turbo#5248136953412540290
by unmounting it, i may have a great access to the sump without unmounting it, do you think it could be possible ?
Thanks

 

[oliviersp1]

i found the last ball, it was in my plastic tub i use to get the used oil...
so only the balls housing's are missing, don't know where it can be !

 

[compress ignite]

Part "To the Right" on your oil sump

That's the "Side Pan" it Unbolts /Bolts and is removable (You may need a new gasket for it if you remove it.)

 

[oliviersp1]

Hi,
yes that's what i was thinking, i will remove it, it's much easier than removing the sump because i have only jack stands.

look, that's "Art"
http://picasaweb.google.com/oliviersp1/Mercedes_300D_turbo#5248380841461669602

nobody knows for the ball's housings ?

Thanks

 

[Dieselman]

Did they definately reside in a cage.?