Air condition? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

The Hogdoctor · 12-26-2005, 09:42 PM

I have bought a 1978 Chevrolet pickup with 78,000 orgional miles on it. The air condition belt is off the compressor and don't know if it works.I asked the person about it and he said that the truck was like that when he bought it 3 years ago. He said that he only drove it in the winter time to the hunting club and did not need the air.
My question is: If I need to change the compressor,(R12) freon can I use the new gas called Freeze 12, or will It be easier to change to the new freon called R134a.
I have been told that the new change over kits do not work well.

**smokinn** · 12-26-2005, 10:33 PM

I would just change it over to 134a and be done with it. BUt before you do all that might as well toss on a belt and make sure the compressor works.

Slonaker · 12-27-2005, 01:03 AM

I have converted my newer style R4 compressor to R134, and I have not had any problems with it.

I would be really surprised if yours only needed a belt. If it worked, why wouldn't the y just fix it? I would be rich if I had a dollar for every time the owner of a used vehicle said it just needed a belt, or that it just needed freon.

Slonaker

The Hogdoctor · 12-27-2005, 10:04 PM

I am afraid there is more wrong with this air than just a belt,like some of you said.
I will try a belt first and see. If there is a leak in the system then I will change it over this summer.
I know this sounds like I am a idiot,but I am tired of throwing money at this truck to see if it works and finding out it was something else. That is the way its been since I bought it.

Thanks for the response, you helped me make up my mind.

Slonaker · 12-28-2005, 01:11 AM

No, that does not sound idiotic at all. I would start with the cheap and simple stuff first. I just would not be real hopeful that it would fix it.

Whenever something breaks on my truck, it is always something odd an expensive. I always hear, "Wow, I've never seen that happen before!"

Slonaker

fiream · 12-28-2005, 02:16 AM

Unfortunately a missing belt usually means a locked up compressor so before you even buy a belt I would check. If the system is intact otherwise, you should be able to hear a loud click when you move the selector to A/C. That is the compressor clutch locking in. With the clutch locked in (engine off), try to turn the clutch/pulley assembly by hand. If it turns without too much effort the compressor is likely good. If it won't turn at all it's locked up and you have serious problems.
If you can't get the clutch to lock in the system is probably empty and has a leak. Check the electrical connector at the clutch and see if it's making a good connection and check for 12vdc. If no voltage, check the pressure switch at the evaporator. The system needs minimum pressure to activate this switch and the clutch. You can jumper past this switch and see if the clutch engages. If it does, the system is empty but you can then easily try turning the compressor. If you get lucky and the compressor is not locked up but the system is empty you will need to look for the source of the leak.
Good Luck,
Fiream

piecesparts · 12-28-2005, 07:56 PM

A lot of the "OLD TIMER" thinking was to remove anything that might be robbing the gas mileage. The country boys did not care for that A/C stuff so they usually cut the belt to get rid of anything that might cost them later. I used to do it for them in the shop, years ago.

12-26-2005, 09:42 PM	#1
The Hogdoctor Registered User Join Date: Nov 2005 Location: Mount Olive Al Posts: 65	Air condition? I have bought a 1978 Chevrolet pickup with 78,000 orgional miles on it. The air condition belt is off the compressor and don't know if it works.I asked the person about it and he said that the truck was like that when he bought it 3 years ago. He said that he only drove it in the winter time to the hunting club and did not need the air. My question is: If I need to change the compressor,(R12) freon can I use the new gas called Freeze 12, or will It be easier to change to the new freon called R134a. I have been told that the new change over kits do not work well.

12-26-2005, 10:33 PM	#2
smokinn Senior Member Join Date: Aug 2002 Location: omaha,Ne Posts: 619	Re: Air condition? I would just change it over to 134a and be done with it. BUt before you do all that might as well toss on a belt and make sure the compressor works.

12-27-2005, 01:03 AM	#3
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Air condition? I have converted my newer style R4 compressor to R134, and I have not had any problems with it. I would be really surprised if yours only needed a belt. If it worked, why wouldn't the y just fix it? I would be rich if I had a dollar for every time the owner of a used vehicle said it just needed a belt, or that it just needed freon. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

12-27-2005, 10:04 PM	#4
The Hogdoctor Registered User Join Date: Nov 2005 Location: Mount Olive Al Posts: 65	Re: Air condition? I am afraid there is more wrong with this air than just a belt,like some of you said. I will try a belt first and see. If there is a leak in the system then I will change it over this summer. I know this sounds like I am a idiot,but I am tired of throwing money at this truck to see if it works and finding out it was something else. That is the way its been since I bought it. Thanks for the response, you helped me make up my mind.

12-28-2005, 01:11 AM	#5
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	Re: Air condition? No, that does not sound idiotic at all. I would start with the cheap and simple stuff first. I just would not be real hopeful that it would fix it. Whenever something breaks on my truck, it is always something odd an expensive. I always hear, "Wow, I've never seen that happen before!" Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

12-28-2005, 02:16 AM	#6
fiream Registered User Join Date: Dec 2005 Location: BFE Texas Posts: 6	Re: Air condition? Unfortunately a missing belt usually means a locked up compressor so before you even buy a belt I would check. If the system is intact otherwise, you should be able to hear a loud click when you move the selector to A/C. That is the compressor clutch locking in. With the clutch locked in (engine off), try to turn the clutch/pulley assembly by hand. If it turns without too much effort the compressor is likely good. If it won't turn at all it's locked up and you have serious problems. If you can't get the clutch to lock in the system is probably empty and has a leak. Check the electrical connector at the clutch and see if it's making a good connection and check for 12vdc. If no voltage, check the pressure switch at the evaporator. The system needs minimum pressure to activate this switch and the clutch. You can jumper past this switch and see if the clutch engages. If it does, the system is empty but you can then easily try turning the compressor. If you get lucky and the compressor is not locked up but the system is empty you will need to look for the source of the leak. Good Luck, Fiream

12-28-2005, 07:56 PM	#7
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: Air condition? A lot of the "OLD TIMER" thinking was to remove anything that might be robbing the gas mileage. The country boys did not care for that A/C stuff so they usually cut the belt to get rid of anything that might cost them later. I used to do it for them in the shop, years ago.



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