changing ac compressor

[pina4greg]

I am going to attempt to change my ac compressor on my 1992 w140 300se.
Can I just undo the connections or is it pressurized and need special tools? also the compressor I am getting from the States comes with no oil. Do I need to fill it before install or can I install and then get it filled and gassed later as long as I don't turn it on. In other words can I just connect it and then drive it to get it gassed etc???

New tried this sort before so sorry if its a dumb question.....

Cheers

Greg

[Tony From West Oz]

When I changed mine I didn't turn the A/C on until it was gassed up.
If it is not filled with oil, then don't run it until lubed and gassed.

[Ivanerrol]

There will be a schrader valve on the high side piping.
Just give the little pin in the valve a gentle push - if there's any gas in there you will know.

If there is gas in there, go down to your local AC fill-up place and have all the current gas vacuumed out. They'll vaccum out the ester oil as well.
When it comes to fill up they will add oil and a trace colour (colour to detect leaks).
When you have the system apart, get all the old seals and take them to your AC guy. get new seals of him - he may charge you nothing for these as you will go back to get the gas reinstalled. There will be two seals on the compressor and one each on the high and low pressure lines.
You should be renewing the drier - the new one should comes with seals.

I remove the high pressure hose pipe first when the car is sitting on the ground. In your case the drier hoses as well.
Remove the serpentine belt. This may require removing the fan shroud which in turn may require removal of the fan blades.
Then lift the car and remove the engine cover.
Your compressor should be a four bolt model - maybe a three bolt. There may not be enough room to remove the bolts from the compressor. undo the bolts and let them loose.
The compressor should come out. The compressor on my W202 came out from the bottom. The compressor on the W210 came out the top.
Reinstall is reversal of the process.

When installing the seals make sure you lube them with a little bit of ester oil.

[pina4greg]

Thanks guys, I did supply my vin to Pelican Parts to make sure I got the correct compressor so "should" fit...
Will follow the advice. So the car is safe to drive with the new compressor installed without oil or refrigerant in it as long as I dont turn the ac on?

[Ivanerrol]

The drier has a little pressure switch on the top. (you will need to relocate this switch to your new drier).
If there is no gas in the system or too little gas the detector switch on the drier wont let the electric clutch on the compressor to activate.
You can push the EC button or AC button on the controller until the cows come home - but the compressor will not start.

Plenty of cars running around with no gas in the AC system.

[pina4greg]

I will need to jack up the front of the car to access the compressor and will need jack stands.

Where is the best place to place them under the car?

Obviously will be using the jack position on the car to lift it.

Cheers

Greg

[Tony From West Oz]

Use the supplied jack to lift the car using the jacking holes in the rocker panels. Add car stands under the body just inboard of the jacking points. Usually there will be a rubber block on the rail at that point.