Air Conditioning Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WI_Jeff · 08-07-2017, 02:35 PM

First of all, I hope I posted in the right area. Second, I got rid of my 1967 Chev School bus (converted to a camper). I didn't want to do it, but, my knees were too bad to use the clutch anymore. I upgraded to a 1987 Winnebago with the

P30 Chevrolet chassis and the 454 engine.

Enough gabbing, here is my problem. I noticed that the air conditioning compressor was real "black" all around the clutch. Found a replacement compressor. When taking the old compressor off, there was some pressure in the lines. I replaced the compressor, cleaned the condenser in front of the radiator and put in new O-rings everyplace I took apart. Because this was the old R12 system, I also put the new R134a fittings on the compressor. Now here it sets. I have the oil and the R134a to fill it, but, do I need to do anything else before I add this to the system? As I said, everything is back in but the new compressor has not been plugged in as of yet. Any help would be great as I don't know much about air conditioning. Thanks again... Jeff

Andy4639 · 08-08-2017, 07:58 PM

Hook it all back up and take it to a shop and let them pull a vacuum on it and add the right amount of oil and 134-A freon.
At the very least I would replace the orfice tube and the acumalator before vacuuming it though. Both are pretty easy to do and don't cost that much and are the main problems in these system's.

Dead Parrot · 08-08-2017, 08:28 PM

What Andy4639 said but add a AC system flush to the job. The old R12 oil doesn't always play well with the new oil for a 134 system. Since it is already open, now is the time for a flush. Plus you don't know what a PO has added. They might have tried some R-12 substitute and a corresponding weird oil. Consider getting a new dryer unit as well. Sometimes the warranty on a compressor will specify a new dryer as a condition for the warranty.

Have them inspect the lines to/from the compressor. If by chance they are still the original lines, they are probably end of life.

If the AC shop asks, there was NO pressure in the system when you pulled the old compressor. Venting R-12 to the air is a legal no-no. Does it happen? Sure. Just don't admit it.

Andy4639 · 08-09-2017, 09:29 AM

If the AC shop pulls a good 30 minute vacuum min the oil and old freon will be pulled out of the system and what is not is burnt off by the vacuum. Never ever tell a shop you vented it out.

WI_Jeff · 08-09-2017, 11:05 AM

Thanks a bunch. I'll check on the orfice tube and the acumalator. THEN I will get it to a shop and vacuum before I use the system.

08-07-2017, 02:35 PM	#1
WI_Jeff Registered User Join Date: Jun 2009 Location: Cadott, WI Posts: 10	Air Conditioning Help First of all, I hope I posted in the right area. Second, I got rid of my 1967 Chev School bus (converted to a camper). I didn't want to do it, but, my knees were too bad to use the clutch anymore. I upgraded to a 1987 Winnebago with the P30 Chevrolet chassis and the 454 engine. Enough gabbing, here is my problem. I noticed that the air conditioning compressor was real "black" all around the clutch. Found a replacement compressor. When taking the old compressor off, there was some pressure in the lines. I replaced the compressor, cleaned the condenser in front of the radiator and put in new O-rings everyplace I took apart. Because this was the old R12 system, I also put the new R134a fittings on the compressor. Now here it sets. I have the oil and the R134a to fill it, but, do I need to do anything else before I add this to the system? As I said, everything is back in but the new compressor has not been plugged in as of yet. Any help would be great as I don't know much about air conditioning. Thanks again... Jeff Last edited by WI_Jeff; 08-07-2017 at 02:37 PM. Reason: Forgot item

08-08-2017, 07:58 PM	#2
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: Air Conditioning Help Hook it all back up and take it to a shop and let them pull a vacuum on it and add the right amount of oil and 134-A freon. At the very least I would replace the orfice tube and the acumalator before vacuuming it though. Both are pretty easy to do and don't cost that much and are the main problems in these system's. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

08-08-2017, 08:28 PM	#3
Dead Parrot Registered User Join Date: Aug 2012 Location: Oklahoma City, OK Posts: 2,472	Re: Air Conditioning Help What Andy4639 said but add a AC system flush to the job. The old R12 oil doesn't always play well with the new oil for a 134 system. Since it is already open, now is the time for a flush. Plus you don't know what a PO has added. They might have tried some R-12 substitute and a corresponding weird oil. Consider getting a new dryer unit as well. Sometimes the warranty on a compressor will specify a new dryer as a condition for the warranty. Have them inspect the lines to/from the compressor. If by chance they are still the original lines, they are probably end of life. If the AC shop asks, there was NO pressure in the system when you pulled the old compressor. Venting R-12 to the air is a legal no-no. Does it happen? Sure. Just don't admit it.

08-09-2017, 09:29 AM	#4
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: Air Conditioning Help If the AC shop pulls a good 30 minute vacuum min the oil and old freon will be pulled out of the system and what is not is burnt off by the vacuum. Never ever tell a shop you vented it out. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

08-09-2017, 11:05 AM	#5
WI_Jeff Registered User Join Date: Jun 2009 Location: Cadott, WI Posts: 10	Re: Air Conditioning Help Thanks a bunch. I'll check on the orfice tube and the acumalator. THEN I will get it to a shop and vacuum before I use the system.



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