Experiences sought on this one. My 300TE has a freshly rebuilt air pump with only about 4 months use or about 6k miles. The front bearing is screaming on it already and it's blowing that burnt red dust out that is reminiscent of the last pumps front bearing innards. I replaced the vacuum check valve upstream of the air pump with a brand new valve when I replaced the air pump.

Has anybody else had this short of life from a rebuild. I think the pump is seized again, I'm going to try to turn it by the nut on the clutch tomorrow. I disconnected the pump electrically and it seems to be running without all of the painful noise, so I'm going to be checking my warranty out on it. Hopefully it was a 6 month warranty and not 3 months.

Your inputs are greatly appreciated.

Where did you get the part? Remember, there are 2 bearings in play here. One that is the idler portion and one that is on the front of the shaft that rotates when the electric clutch comes on..;.

__________________
Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Benzmac,

I got the pump from Randy Steele at EPS. He's been very good in the past on support. I didn't think you guys were up back in December/January.

The car runs without complaint with the pump electrically disconnected. I can't turn the pump via the nut on the end of the pulley so I expect the pump itself is seized and I"m burning up the electric clutch when it is coneected and trying to work.

I'll call Randy tomorrow.

Thanks for the input.

Mike, did you resolve your pump issue? I am interested in replacing my pump.

I bought a used pump from a luxury salavage yard here in Canada. It wasn't a rebuild, but it came with a two year warranty. Cost me a third what MB wanted for a new one. Does your rebuild have a warranty? Whoever you bought it from should replace it in that short amount of time.

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Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired

Here's where I stand on the air pump issue:

I have installed the replacement rebuild from Randy Steele at EPS and I'm going out to finish the install as soon as I'm done this post. The new pump is in and the belt is back on. I just have to tension the belt and put the fan back on. I'm going to place the plug connector ends directly next to each other and heat shrink wrap the joint. It will look very nice and ensure the pump doesn't ever run. I look at it like a $400 idler bearing that will not fail again unless the bearing gets tired, but the first one lasted 160k miles, so I'm optimistic. I learned you don't get the check engine light if you disconnect the airpump, at least on a 1991 model.

The warranty should cover the replacement, I'm not out of the woods yet because they are asking for documentation that I replaced all of the valves and hoses in the discharge side of the pump. I replaced the diverter valve and cleared the two small plastic hoses before re-installing. Randy thinks that should be enough for the mfr to honor the warrranty, but I'll let you all know if I get hung out to dry. I think Randy is doing his best to take care of me.