Vacuum pump replacement w124 601 (whith pics)
 

Hi gentlemen,

I decided to replace the vacuum pump of my baby, and since i had replaced the pump of my w201 3 months before i totaled it, instead of buying a new one i decided to use the 3 months old one of the w201 :D, just bought a new gasket!;)

Here's a litlle help to everyone who wants to replace it to:

1st you have to remove the hose that's atached to the fan cover:

Then it's time for the fan cover, but first you have to remove the fan.
Just remove the 2 clips holding the cover:

Then tilt the cover so tou can reach your arms in between the radiator and the cover and unscrew the screw that holds the fan, then just pull it out and remove the cover:

Now you have more room to work on:

Now it's time for the belt to come out, with no belt the job is alot easier!

Insert a lever in the tensioner and push a bit down so you can push the bolt back after you remove the nut, then remove the spring and the belt will be loose, just remove the belt or pull it aside!

disconect the hoses from the pump:

No belt and no hoses:

Time to remove the pump, there are six screws, just unscrew a bit at a time each one cause the spring inside the pump can be under pressure!
Remove the pump and the old gasket!

Here's my old gasket, it's cracked cause the wrong one was used::eek:

New and right gasket VS old and wrong gasket:

"New" pump:

Now to put the new pump you got to rotate the engine because the lumps have to stay up and down so that the roller in the pump doesn't meet a lump when screwing the new pump or the spring of the pump won't let you put the pump in place!

After cleaning the engine and pump surface, put the new gasket and pump in place and screw the screws a bit at a time and alternatly!

thanks, i have to change out the one on my 603. I have the old style:eek: need the updated one.

Now put the belt in place, the spring of the tensioner, the screw and nut of the tensioner, the cover of the fan, the fan and clips of the cover and you are ready to go!

Ruben, how can I tell if I have the "new" or "old" style vacuum pump on my new-to-me 603? I have some work to do (water pump, belt tensioner) and might as well do the vacuum pump too if there's something to be gained.

When this is done do you rebuild the old vac pump, put on a used or new/rebuilt?

I keep reading about needing to do this after so many years. Is there any indication when it is time?

My '81 300D had 400k and I never touched the vac pump. Was I just lucky?

Thanks.

There are many who say that the old-style vacuum pump (cover without bolt heads) should be replaced, period. Do not pass GO, just replace it. There have been a few failures and if a part gets into the oil pump (if driven a while that way) or into the timing chain (more immediate) it can potentially destroy the engine.

There have also been failures of the new style.

I have followed this advice, and replaced mine in past cars, removing the perfectly good old-style and tossing it. It is supposed to be non-rebuildable.

Currently I have changed my tack. Whether it is a good idea or not, others will debate. Anyway, I still have the last one I removed, and am building an engine for my car, removed the one currently in the car also. They are both perfect, work well, bearings smooth and tight, I see no reason to toss them and will be re-installing the vacuum-pump. This after spending thousands on upgrades? It seems to me that inspecting a part, finding it to be good, and reinstalling is what keeps aircraft in the air, especially since we know the failure mode is for the bearing to wear out and lose the cage. It can be inspected easily.

So replace yours, it is good insurance, I'll run mine another year and inspect it, or replace it next time I need a belt, we'll see.

The one you took off was the new style, why did you take it off? How many miles were on it?

Thanks Jeff.

That's my question as well, the removed vac pump appears to be the new style which would suggest that someone already replaced the original, do you think it really needed to be replaced?

steve a