91vettezr1

Hi,
A Few years back I removed all the original freon from my 91 ZR-1. I was doing engine work and needed to remove the a/c hoses for better access. It's been bone dry for a couple years now, what should be replaced upon refilling? Is it ok to use the original dryer and condenser? I have new ones in the box.
thanks
todd

zr1fred

Did you drain the oil or just disconnect? Seal the lines or just leave them open. The reciever drier is basically just an alluminum can with a trap and a bag of desicant in it, there is no filter in it, though you should replace the orifice in the high pressure line. You probably could get by with pulling a vacuum on the system for a couple of hours, and then refilling the system, replacing the oil you feel you may have lost. Down here in Arizona, just about everyone has converted to 134, the system was designed to handle it(94 up actually used it). But if you want to stay with the 12 the procedure is the same. Unless there was a specific problem with the condenser or the evap coils, there should be no need to change them.

Sgreg

I have done something similar with another car of mine. I replaced the drier and unfortunately the compressor leaked and it had to be replaced. Seals can dry out and pressure will find the small holes quickly. Won't hurt to try it though and hold your left one when you start it up !

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91vettezr1

I just removed the 1 main a/c hose going to the compressor and oil/freon was released . re-installed the main a/c hose and that was it. never refilled the system.that was 2 yrs ago

dallas916

If the system has been closed all this time you probably won't need much more than a recharge. Has the compressor been turned at all? Normally, with the gas gone the low pressure switch won't allow the clutch to kick the compressor on, but there are ways to bypass the switch.

If the system has been closed I would do this:

1- turn the compressor by hand or bypasss the switch and turn it with the engine just cranking (not running) to get the parts moving again.

2- buy some "Freeze 12" or "Enviro-Safe", one can with the oil added, and put it into the system and run it. I use Enviro-Safe, but I hear Freeze 12 is fine, too. It's only about $5/can and is compatible with either R134 or R12. You can check for leaks and cooling efficiency without spending a fortune.

3- If you have leaks you can take care of them or have the system vacuumed down. Actually, renting a vacuum pump and getting any contaminants or moisture out of the system is probably a good idea anyway. So get a couple of extra cans of juice and recharge after the vacuum/leak check. You won't need to change fittings with the ES or F12 gasses, but you will if you go to R134.

Goldcylon

Todd I would replace the receiver dryer and condensor. Why for all the reasons listed below but on a 91 you have 17 years of accumlicated crud and suspended waste that was collected in those systems. Just my .02

terryszr1

i found out the hard way loosing a compressor trying to do it the cheap way.then had a friend who does air conditioning for gm come help me. he had me do what was suggested above and all is now well. in the end those parts are way cheaper than the compressor (about800) with clutch.

kalister1

If you already have the drier use it. I had a desiccant bag break, that sent JUNK all through the system.

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dallas916

I've recharged/rebuilt/replaced a number of systems over the years and never had to replace the condensor. Unless it was a corroded piece of junk or had fin/tube/fitting damage I've never seen an honest shop replace one.

There is also a flushing process that can be done if you don't think vacuuming is enough. You can do it yourself if you want to take the time. Any pro shop you take the car to will charge $700-1200 for the whole job and conversion....not including a compressor or condensor.