Hi all,
Last week the AC compressor on my 97 Corvette locked up. I was going to have it replaced at the dealership, but due to some cash flow constraints that isn't an option right now. I have already purchased a new GM compressor, accumulator, oriface, and belt. I have very little AC system experience so I am a little nervous about doing the install.

My questions are:
1. Can I evacuate the system without taking it somewhere with a recovery system, and are there any adverse affects to doing it this way? I realize the method may not be environmentally friendly but I am willing to recycle more beer cans to make up for it. :cheers:

2. I understand there needs to be oil in the system but I have no idea how much or where or when to put it in. Do I pour some in the new accumlator or compressor during the install? If so, how much do I put in each component?

3. What type of oil do I need for the system? I bought some Castrol PAG 150 at the autoparts store, but I am not convinced this is the right stuff. It does say on the back "Meets GM material specification #9985752". Is that the spec I need to meet?

4. The service manual says to seal the hose ends while they are not connected. I was thinking of wrapping them up good with electical tape while they are off. Is that sufficient?

5. Is there anything else I need to watch out for?

 

Your on the right track....look for metal debris in the ines..don't want that. System is a 134A system so it is supposed to be more enviromentaly friendly if vented into the air vs. recoverd. System should have vacum pulled on it if it has been opened to boil any moisture out, but I have done driveway compressor changes without and had no problem. I'm not sure on the capacity of coolant (check w/service manual) but 2-2 1/2 ...sometimes 3 cans is common in other systems. change out compressor & reciever/dryer and orfice screen (may need to remove water pump & drain/save coolant ) hook up refill to low-side (new systems have diiferent size adaptors for high & low so you shouldn't get mixed up.) and release coolant into system. Start car with air on and finish filling from first can. Then add oil & second can (oil comes in a small can as well that will fit the adaptor), and so on. Should be blowing cold by second can. Not a hard project, just go slow & careful. GOOD LUCK!


[Modified by TLewis4095, 6:17 PM 9/28/2001]

 

What about oil in the coolant system? Do I need to put some in there or is the R134a all I need?

Thanks,
Seth

 

It is really best to pull a vacuum, but if you can't, fill from the low side (blue hose on gages) and bleed off for about 30 seconds from the high side (red hose). Check to see if your compressor already has oil in it before you charge the system. If you're not sure, call the dealership. Many compressors already come charged with oil. If you overfill it, you will end up trying to compress oil and break the compressor in the process. Many new compressors have the required oil charge listed on them. If the compressor is already off the car you are better off to just pour the oil in through the compressor fill/ drain plug.) Do NOT pour oil into the low side port. (see comment above about trying to compress oil). The low side port is the one that connects to the line that comes from the receiver/dryer near the firewall. It is good practice to check for leaks after you put in one can of refrigerant. You can make up a solution with dishwashing soap, brush it on, and look for bubbles (just check the joints where you opened up the system). In terms of charge, whe the receiver is cold enought to sweat (not a problem in Georgia) your charge is about right. Good luck!