Thought someone might need one - The 1947 - Present Chevrolet & GMC Truck Message Board Network

66 lwb cs · 07-02-2011, 10:39 AM

I thought someone might be interested in this seems like a good price.
Not mine I already have A/C not vouching for it and have no vested interest other than helping other members find good stuff.

http://denver.craigslist.org/pts/2412822030.html

chevyrestoguy · 07-02-2011, 11:19 AM

The old knee-freezer! Those things work great if you are looking to retrofit A/C into your truck. Plus, it'll leave your firewall clean because the evaporator is inside the underdash unit.

I've got an old Mark IV underdash unit on my parts shelf that'll eventually go into something later.

Martin64 · 07-02-2011, 11:27 AM

Not to take this thread too far off track, but I have something similar out of an old F***. My question is what in the system needs the work to convert it to R135. I don't have a compressor yet, so is that something I dont need to worry about if I buy a current compressor out of a newer junked car?

64fleetside · 07-02-2011, 05:19 PM

Nearly any compressor will work w/R134a, the key component in R12=R134a is the condenser-score a R134a condenser(I bought an aftermarket unit designed for 60-66) and it will work fine-my fact AC(all designed for R12) is putting out 45* air out the vent w/95* shop temp.

An R12 condenser will give high head pressure on R134a & has killed many compressors.

chevyrestoguy · 07-02-2011, 10:11 PM

Quote:

Originally Posted by 64fleetside

Nearly any compressor will work w/R134a, the key component in R12=R134a is the condenser-score a R134a condenser(I bought an aftermarket unit designed for 60-66) and it will work fine-my fact AC(all designed for R12) is putting out 45* air out the vent w/95* shop temp.

An R12 condenser will give high head pressure on R134a & has killed many compressors.

Is it an orifice size issue? I have heard this as well, but nobody ever explained the exact reason.

smallblock kid · 07-03-2011, 12:53 AM

the orffice tubes are different infact r12 is used at a higer pressure than R134A and the oil that is used in the systems to lubricate is different the fittings have to be changed along with a few hoses and the entire system must be evactuated before the conversion

Rooster's 67 · 07-03-2011, 03:47 PM

the hoses have to be current or new style R134a compatible hoses, the R134a molecule is smaller than the R12 and will seep through older R12 hoses. also the expansion valve or orifice must be designed for R134a due to different operating pressures.

07-02-2011, 10:39 AM	#1
66 lwb cs Registered User Join Date: Apr 2011 Location: aurora co Posts: 208	Thought someone might need one I thought someone might be interested in this seems like a good price. Not mine I already have A/C not vouching for it and have no vested interest other than helping other members find good stuff. http://denver.craigslist.org/pts/2412822030.html __________________ 66 C20 LWB CS 327/TH400 A/C

07-02-2011, 11:19 AM	#2
chevyrestoguy Registered User Join Date: Mar 2005 Location: apple valley, ca Posts: 2,670	Re: Thought someone might need one The old knee-freezer! Those things work great if you are looking to retrofit A/C into your truck. Plus, it'll leave your firewall clean because the evaporator is inside the underdash unit. I've got an old Mark IV underdash unit on my parts shelf that'll eventually go into something later. __________________ Check out my latest endeavor: https://roundsixpod.com My build threads: '55 Chevy: http://67-72chevytrucks.com/vboard/s...d.php?t=247512 '64 C-20: http://67-72chevytrucks.com/vboard/s...d.php?t=446527

07-02-2011, 11:27 AM	#3
Martin64 Registered User Join Date: Oct 2003 Location: Yuma, Az Posts: 477	Re: Thought someone might need one Not to take this thread too far off track, but I have something similar out of an old F**. My question is what in the system needs the work to convert it to R135. I don't have a compressor yet, so is that something I dont need to worry about if I buy a current compressor out of a newer junked car? __________________ Martin Gibson USAF Retired 1964(-ish) C10*

07-02-2011, 05:19 PM	#4
64fleetside Registered User Join Date: Apr 2004 Location: arkieland Posts: 1,070	Re: Thought someone might need one Nearly any compressor will work w/R134a, the key component in R12=R134a is the condenser-score a R134a condenser(I bought an aftermarket unit designed for 60-66) and it will work fine-my fact AC(all designed for R12) is putting out 45* air out the vent w/95* shop temp. An R12 condenser will give high head pressure on R134a & has killed many compressors.

07-03-2011, 12:53 AM	#6
smallblock kid Registered User Join Date: Jun 2009 Location: KS Posts: 107	Re: Thought someone might need one the orffice tubes are different infact r12 is used at a higer pressure than R134A and the oil that is used in the systems to lubricate is different the fittings have to be changed along with a few hoses and the entire system must be evactuated before the conversion __________________ 1966 chevy 1/2 ton freshly rebuilt 350 stock cam performer intake 600 cfm edelbrock 4spd behind it 1986 chevy 4x4 1/2 ton 350 700r4/208 2in lift blocks 31 at tires

07-03-2011, 03:47 PM	#7
Rooster's 67 Registered User Join Date: Sep 2003 Location: DFW Posts: 765	Re: Thought someone might need one the hoses have to be current or new style R134a compatible hoses, the R134a molecule is smaller than the R12 and will seep through older R12 hoses. also the expansion valve or orifice must be designed for R134a due to different operating pressures. __________________ The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?



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