My A/C system recently blew a hose; new hose showed up today (yay!) so tomorrow is going to be replacement day. I'm 90% sure I'm just going to convert to r134.

According to a recent post about the oil in the compressor, I was told I should drop the compressor again and drain out the r-12 compatible mineral oil and replace it with an "equal quantity" of ester PAE-100 oil. My question is: since I blew a hose and consequently have no idea how much oil is now in the system (some, all, or none might've gotten blown out the ruptured hose along with my old refrigerant), why is this a reliable way of telling how much oil to put in the system? Is the compressor sealed or something? I thought the compressor oil circulated through the system just like the refrigerant.

Second question - must I change the receiver / drier? It's pretty new (about 5 weeks old). I was thinking that having a vaccum pulled on the system would evacuate it of all old oil, refrigerant, moisture, etc. Right or wrong? I do have a spare receiver / drier but it looks like crap compared to the one that's in there and has no sight glass.

Finally, can I simply just install the new hose, tighten everything up, take the car down to a shop and have them pull a vaccum on it for a while, then just charge it up myself with those "includes oil" cans of r134? Will that provide enough oil for the compressor? While the shop is pulling vaccum, do they need to rotate the compressor at all to make sure all the old oil is removed? How exactly do I go about this? I sort of don't want to use r-12 again - it's just too damn expensive!

 

Bueller? Bueller?

 

If you want to convert, there's a shop in Pomona of all places that will do the full conversion and a refill of refridgerant, for $130