OK has anyone replaced their airpump on a 400E? Not to much clear info in a search here other than what seems to be the best place to get a remanufactured pump.

My symptoms are that there is a slight squeal (Belt tension is fine and tensioner is about 6 months old). Noise is coming from the left (pasenger) side as you face the car with the hood open. Looks like some bright flakes behind the air pump pully - and the kicker is after a drive the center of the pully is HOT (sizzle to a wet finger). I assume the bearing is shot.

The best deal seems to be mbpumps.com (noted in a search) with a rebuilt for about $200.

Any tricks in replacing the sucker? The MB CD's reference unbolting the engine mount and raising the engine. Is that necessary?

Will order the pump tomorrow but am hoping someone who has done the replacement can give a bit of detail.

Thanks
Paul

You can put a new bearing in the pulley instead of changing it out.

That's true. Seems like the bearing is about $18 if I remember right.

I did mine a few months ago and it's working perfectly.

__________________
2012 E350
2006 Callaway SC560

Thanks, I'll likely give that a try.

But a key here is anyone do this job on a 400E??? I just measured and there is all of 1.25 inches between the front of the air pump pully and the engine fan. So removing the pump to get at the pully and bearing is going to be the diffucult part.

I replaced the fan clutch a couple years ago so I know how tight these engine compartments are.

So again who has pulled the air pump with a M119 engine (400E, E400, 500E, E500)??

Thanks

Paul

Yea,
I changed just the bearing about 3 or 4 months ago. Real difficult to get the pump out. Did not have to remove anything extra to do it.
It took just as long or longer to put back in. I think I came out the side and then up. Only one way works and it took a long time to get it right.

I am doing some other things tonight to it ,so if you have any questions I should remember after I am into it again.


92 400E

Joe

Thanks I got it out, I does kind of come out the side.

Biggest issue is the same thing I ran into when I replaced the throttle body. The rubber hoses have become so hard that they cannot be removed without breaking at least one.

The air pump seems to be toast. When I took off the belt the pullt was loose and wobbliing (not spinning on any type of bearing). Lots of reddish powder everywhere. Given that the clutch kit is about $100 alone I just ordered the rebuilt pump.

I did take a few pictures. Best access comes after removing the dist cap and then the plastic panel under it. You then remove the three bolts holding the air pump bracket in place (previoulsy remove the two bolts for the airpump itself) and then the pump would come ouyt easily - if the hoses were not so HARD and Brittle!

Paul