85 300D - Proper way to install new AC compressor

Jul 16, 2008 2 Replies

Hello all,



I am replacing the AC compressor on my 300D with a NEW unit (not used or rebuilt). The instructions are poor that they provide as the proper way to set up the system. I installed a used compressor about



4 years ago, but the shaft seal is now leaking. When I installed that unit, I added only some replacement oil ( 2oz) through the fill valve, then R134,

I have heard that new units need to be filled with oil from the bottle, turned 12 times, then installed etc.



Any suggestions? Thanks!


Alot of time, the compressor come filled with oil... if the hose ports are sealed with rubber plugs. However, that is no guarantee. So what most mechanic does is tilt the compressor so the oil will drain out and they measure the amount of oil and compare it to spec.

I do not know what the spec for your car is... and oil is super super important for compressor. There should be a green sticker by the radiator that tells you how much oil you need.

You do need to replace your accumulator also as it may hold some oil too and guarantee that your system is free of moisture.

Changing expansion valve is also highly recommended to make sure it doesn't damage your new compressor.

Question... when you replaced the used compressor, did the compressor have oil or was it empty? Most compressor needs at least 5 oz of oil.

If memory serves, the case of the compressor states 6oz, so I emptied as much oil as possible and filled at back up through the fill valve with 3 of the 2 OZ cans.

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