I have just bought a replacement Air conditionor compressor. I bought the change over kit to change it from R12 to 134a. But, my Bro-in-law gave me 7 cans of R12.
I found a hose that I used on prior cars to recharge the R12. So I'm sure that I can transfer the R12(yes I'm going to return the 134).
I understand that I need to flush the system first, add with oil, and replace gaskets.

What kind and how much oil do I use?

What do I use and how do I flush it?

Which gaskets do I replace?

Thanks so much for the help!

 

No need to flush unless the old compressor seized. If so, I'd replace the condensor as it's nearly impossible to flush. All lines should be removed and then flushed with brake parts cleaner and blown dry with compressed air. The evaporator can be flushed with same, though put a white cloth over one end of it and blow air through it until the cloth remains clean. Flush the replacement compressor by dumping out any oil that is in it. Fill with 4 ozs of fresh oil (mineral oil - just ask for R12 oil at any discounter) and turn the shaft a dozen or so times in one direction and then the same number of turns in the other. Dump the oil and repeat. Leave 4 clean ozs. in it when you install it.

Replace the orifice and accumulator. Put another 4 ozs. of oil in the accumulator.

Use new seals on any lines that you disconnect. A seal kit is available at The Last Detail - www.tld-corvette.com - though a new accumulator and the compressor should come with new seals. Coat all seals with compressor oil.

The AC Delco replacement accumulator has 2 schrader valves. If using it, cut the bracket down so that it fits. Otherwise it will sit up too high and strike the hood.

Pull a vacuum and make sure that it holds before charging.

Capacity is 2.25 lbs or 3 12 oz cans. It's pretty difficult to get every oz. out of a can, so you may need to use some out of a 4th can. Charge until the high side is about 2.2 to 2.5 times the outside air temp, engine at 1200 to 1500 rpms, main fan on (keep the fan on by disconnecting the switch on the high pressure line).

Once charged, verify the setting of the low pressure switch by leaving the a/c on high and disconnecting the blower. Pressure should drop and the compressor should shutoff at 25 psi. If it doesn't, adjust the screw between the terminals clockwise to raise the cutoff; counterclockwise to lower it.

 

Thanks for your help SunCr. I need to find something to create a vacume. Do you know if this can be rented?

 

I couldn't find one at any of the rental outlets in San Diego - all them told me that they didn't think it was legal for anyone other than a licensed a/c tech (and I have one!) to use one. If you have a good size compressor, you can purchase a displacement pump for about 9 bucks from Harbor Freight Tools.

 

I tried the Harbor Freight Tools web page and couldn't find a displacement pump. Maybe I was looking in the wrong place? Do you know where else I can find one?
I have a 5 gal, 3hp, 120 volt air compressor. Do you think that this is big enough?
Thanks

 

Harbour # 3952-3VGA air vacuum pump.

If you don't think you can get all the compressor metal out there is an inline filter you can add to catch any left over debris.

if you use "Ester" AC oil it is compatable with both R12 and R134
and if you ever decide to change to R134 later you will be ok.

 

I use a compressor from an old refrigerator or freezer. You will have to solder the correct adapter to the suction side. I've used this setup for years and it works great, plus it's cheap.

 

Thanks for the numbers. Found it.