New A/C compressor for 400SE - PeachParts Mercedes-Benz Forum

#1 12-11-2002, 03:28 PM

Bought a new A/C compressor for my 400SE. We have no MB mechanics on the island I live on so took my car to a regular repair shop that fixes A/C's on American and some Japannese cars. He has a question about the new compressor. Is it shipped with or with out oil. He said there is usually a tag on the new compressor. I guess he can try to drain the unit to find out but told him I would check it out. Thanks, Steve PS The unit is a new OEM compressor.

engatwork · #2 12-11-2002, 08:51 PM

Where did you purchase the compressor? I would be surprised if it is pre-lubed.

#3 12-11-2002, 10:03 PM

From mercedesshop.com

engatwork · #4 12-12-2002, 06:42 AM

I would be real surprised if it has oil in it then.

#5 12-12-2002, 06:59 AM

My experience has been different than Jim's. I can't remember ever getting one that did NOT have oil. This really is a problem these days, because you don't always know if it has the right kind of oil.

He needs to open the ports, turn the compressor by hand and get out all that he can. Then put some of the oil type he wishes to use in and use it to flush the compressor as thoroughly as possible, then empty as much of that as he can get out.

Then install the compressor into it's brackets and pour in the specified quantity of the desired oil. Then connect all the hoses everywhere and turn the compressor by hand several turns to get a little of the liquid load out of the compressor.

If he does a lot of a/c work, I'm surprised that he does not know to do this. It also makes me wonder if he knows how thoroughly he needs to flush the system after a compressor failure. If there is junk left in the system by not flushing thoroughly, the new compressor will be ruined in short order. If you are replacing the compressor because the seal was leaking then there shouldn't be too contamination to worry about. In that case, he will only have to flush if he is changing refrigerant types.

Good luck,

#6 12-12-2002, 04:11 PM

Will give that info to the guy installing my compressor. Am changeing it because old one was making a loud humming noise. He is going to flush the system also. Hope he knows what oil to use and all. Thanks again, Steve

amg280 · #7 12-13-2002, 11:57 PM

Be sure to use PAG oil. I believe it uses PAG-46. I had to get this oil special when I fixed my AC on my 400. Just pull the plugs out of the new compressor and see if any drains out. That will answer your question.

#8 12-14-2002, 09:48 AM

You will have to do more than pull out the plugs and gravity drain. To get as much oil out as possible, you will have to rotate the compressor by hand with it in a number of positions. Work dilligently and get out as much as possible.

To determine correct oil, go to aircondition.com and then click on "Straight to the Board." Post your question and they will provide an answer in short order. PAG comes in three weights, and 46 may very well be the correct one, but they will know for absolutely sure. There is a guy who will respond as "Chick." You can trust his response.

Good luck,