How Long Does A Recharge Last On A/C - The 1947 - Present Chevrolet & GMC Truck Message Board Network

RipMeyer · 04-07-2002, 08:06 PM

How Long Does A Recharge Last On A/C With Moderate Use?

Does it matter what kind of coolent is used?
R12 - R134?

ebfabman · 04-07-2002, 08:19 PM

Air Conditioning is a "sealed" system. If everything is in good working order it should not need to be charged. However over time some components will begin to deteriorate internally which will affect how the system works.
R12 and R134a are not compatable, they can not be used with one another efficiently

RipMeyer · 04-07-2002, 08:26 PM

Thanks

I am aware of the R12 and R134 not being compatable, I was wondering if one lasted longer than the other.

I have R12 now, Mine seems to work just fine and blows fairly cold However, Would 1 small can be enough to top it up so to speak? And how much is a small can nowadays?

mrein3 · 04-07-2002, 08:39 PM

I put in a new receiver/dryer and new o-rings in my '72 Malibu in the summer of 1989. I topped off the system on my '71 Malibu that same year.
In other words if you have a system without any leaks you shouldn't have to put so much in every so often.
I have read that when the thermometer dips below -20 or -22 F or so you get "winter kill" in your R12 system. When the temp dips below that number your system depressurizes and some R12 escapes. Like I said I've read it and I think I've even heard it on a radio call in car talk show before but I know my cars have been in temps below that in the 10+ years since I've topped them off and they are still working fine.
If your truck never sees those temps you got a leak.

ebfabman · 04-07-2002, 08:45 PM

Rip, you got any AC techs that can help you?

The reason I ask is you really need to put gauges on that system to check proper charge, system condition, etc.

Without the gauge readings its just a "shot in the dark" as to how much refrigerant is in the system.
I know this doesn't help much but even though many people charge AC systems, there are chemical reactions that take place which produce products that slowly "eat away" at the system if not handled properly

70shortnphat · 04-07-2002, 08:58 PM

All a/c systems leak always.(on a molecular level). Just like the air pressure in your tires.
The amount of pressure in the system is directly related to the ambiant temp.The hotter it is out side the higher the pressure in the system. There is a formula for calculating what the high and low pressures should read on your system based on ambient temp.(have in a book somewhere).
The worst enemy of your system moisture.
The reaction of chlorofluorocarbons to moisture is hydrocloric asid.that is why if an a/c system has been exposed to outside atmosperes(no freon),you can get what looks like battery acid on the fitting and in side the system.

------------------
1970 short bed fleetside

imaindianoutlaw · 04-07-2002, 09:19 PM

The oil absorbs the moisture and turns to acid! Poly ester oil which is used on 134a has a very high absorbtion rate and will turn to an acid that will affect your skin in a minor burn! This is a sealed system and as long as its a good sealed system you should not have to add any refrigerant. R12 and 134a are very much alike pressure respect. If your system does have a leak a good hot day your refrigerant will find it. You can add refrigerant til pressures are correct but to make sure you have a correct charge you should Recover what is in the system weigh it and if its low pump up with nitrogen and search for leaks. Repair leak and charge to factory specs. When systems sit not being in operation, the suction side of the system contains a higher pressure and can find small leaks and escape. Most likely in residential Air conditioning when system are not being used in the winter time!

------------------
Charles W. Hein
S. Williamsport PA

imaindianoutlaw@yahoo.com

REFRIGERATION TECH

1971 Rolling chassis

FOR SALE
1963 Pontiac Tempest
1965 Pontiac GTO
1956 Pontiac 2 dr

**Desert Rat** · 04-07-2002, 09:31 PM

If you dont have the gauges etc i wouldnt do it,my stepdad has a bunch of r12 cans thought hed add some well he did and it was too much-ruined the compressor.

**Desert Rat** · 04-07-2002, 09:34 PM

I heard r12 cools better,but ive never had both to compare-just what ive heard-but it is alot more spendy-and it shouldnt take much to cool off the inside of a cab,its a small area to cool.long as you have good weatherstrip and no big rustholes in the firewall-make sure that cab is sealed up good.

RipMeyer · 04-07-2002, 10:39 PM

The A/C works great. I was just wondering if it needed any attention or preventive maintenance in the very near future.

Thanks For the Replys

Andy4639 · 04-08-2002, 12:50 AM

Run your system every once in a while during the winter to keep the system going and o-rings lubed, and it will last a lot longer. If you don't have the gauges wouldn't try and top off the system.

------------------
Andy
71's Are for ever!!! or 67,68,69,70,72 http://geocities.com/chevy71tpi/main.html

Project1970 · 04-08-2002, 02:56 AM

As long as it's cold, you shouldn't need any.

I know mine needs some (I've got gauges and a stash of R12 my dad snagged while it was cheap, woo!) since it's historically needed about a can a year...but now I think it needs more, it's never been this warm at the start of a summer...

Eh, either way, I'll run R12 until I run out of it, then rebuild the system and go R134a.

------------------
Project 1970 - soon to be seen at http://milhouse.treylis.org:81/

04-07-2002, 08:06 PM	#1
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	How Long Does A Recharge Last On A/C How Long Does A Recharge Last On A/C With Moderate Use? Does it matter what kind of coolent is used? R12 - R134?

04-07-2002, 08:39 PM	#4
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	I put in a new receiver/dryer and new o-rings in my '72 Malibu in the summer of 1989. I topped off the system on my '71 Malibu that same year. In other words if you have a system without any leaks you shouldn't have to put so much in every so often. I have read that when the thermometer dips below -20 or -22 F or so you get "winter kill" in your R12 system. When the temp dips below that number your system depressurizes and some R12 escapes. Like I said I've read it and I think I've even heard it on a radio call in car talk show before but I know my cars have been in temps below that in the 10+ years since I've topped them off and they are still working fine. If your truck never sees those temps you got a leak. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

04-07-2002, 08:58 PM	#6
70shortnphat "See the U.S.A....." Join Date: Apr 2002 Location: Richmond TX. Posts: 269	All a/c systems leak always.(on a molecular level). Just like the air pressure in your tires. The amount of pressure in the system is directly related to the ambiant temp.The hotter it is out side the higher the pressure in the system. There is a formula for calculating what the high and low pressures should read on your system based on ambient temp.(have in a book somewhere). The worst enemy of your system moisture. The reaction of chlorofluorocarbons to moisture is hydrocloric asid.that is why if an a/c system has been exposed to outside atmosperes(no freon),you can get what looks like battery acid on the fitting and in side the system. ------------------ 1970 short bed fleetside __________________ 1970 short bed fleetside 1949 all origional chevy 3600 1974 camaro Richmond , Texas(just S.W.of Houston)

04-07-2002, 09:19 PM	#7
imaindianoutlaw GMC SHORT FLEET F/S Join Date: Jun 2000 Location: SOUTH WILLIAMSPORT PENNSYLVANNIA Posts: 2,117	The oil absorbs the moisture and turns to acid! Poly ester oil which is used on 134a has a very high absorbtion rate and will turn to an acid that will affect your skin in a minor burn! This is a sealed system and as long as its a good sealed system you should not have to add any refrigerant. R12 and 134a are very much alike pressure respect. If your system does have a leak a good hot day your refrigerant will find it. You can add refrigerant til pressures are correct but to make sure you have a correct charge you should Recover what is in the system weigh it and if its low pump up with nitrogen and search for leaks. Repair leak and charge to factory specs. When systems sit not being in operation, the suction side of the system contains a higher pressure and can find small leaks and escape. Most likely in residential Air conditioning when system are not being used in the winter time! ------------------ Charles W. Hein S. Williamsport PA imaindianoutlaw@yahoo.com REFRIGERATION TECH 1971 Rolling chassis FOR SALE 1963 Pontiac Tempest 1965 Pontiac GTO 1956 Pontiac 2 dr __________________ CHARLES WADE HEIN HVACR FOREMAN. LEWISBURG U.S.P.

04-08-2002, 12:50 AM	#11
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Run your system every once in a while during the winter to keep the system going and o-rings lubed, and it will last a lot longer. If you don't have the gauges wouldn't try and top off the system. ------------------ Andy 71's Are for ever!!! or 67,68,69,70,72 http://geocities.com/chevy71tpi/main.html __________________ 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.

04-07-2002, 08:19 PM	#2
ebfabman Registered User Join Date: Nov 2001 Location: Concord, NC Posts: 2,489	Air Conditioning is a "sealed" system. If everything is in good working order it should not need to be charged. However over time some components will begin to deteriorate internally which will affect how the system works. R12 and R134a are not compatable, they can not be used with one another efficiently

04-07-2002, 08:26 PM	#3
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	Thanks I am aware of the R12 and R134 not being compatable, I was wondering if one lasted longer than the other. I have R12 now, Mine seems to work just fine and blows fairly cold However, Would 1 small can be enough to top it up so to speak? And how much is a small can nowadays?

04-07-2002, 08:45 PM	#5
ebfabman Registered User Join Date: Nov 2001 Location: Concord, NC Posts: 2,489	Rip, you got any AC techs that can help you? The reason I ask is you really need to put gauges on that system to check proper charge, system condition, etc. Without the gauge readings its just a "shot in the dark" as to how much refrigerant is in the system. I know this doesn't help much but even though many people charge AC systems, there are chemical reactions that take place which produce products that slowly "eat away" at the system if not handled properly

04-07-2002, 09:31 PM	#8
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	If you dont have the gauges etc i wouldnt do it,my stepdad has a bunch of r12 cans thought hed add some well he did and it was too much-ruined the compressor.

04-07-2002, 09:34 PM	#9
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	I heard r12 cools better,but ive never had both to compare-just what ive heard-but it is alot more spendy-and it shouldnt take much to cool off the inside of a cab,its a small area to cool.long as you have good weatherstrip and no big rustholes in the firewall-make sure that cab is sealed up good.

04-07-2002, 10:39 PM	#10
RipMeyer Registered User Join Date: Oct 2001 Location: Southern New Mexico Posts: 649	The A/C works great. I was just wondering if it needed any attention or preventive maintenance in the very near future. Thanks For the Replys

04-08-2002, 02:56 AM	#12
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	As long as it's cold, you shouldn't need any. I know mine needs some (I've got gauges and a stash of R12 my dad snagged while it was cheap, woo!) since it's historically needed about a can a year...but now I think it needs more, it's never been this warm at the start of a summer... Eh, either way, I'll run R12 until I run out of it, then rebuild the system and go R134a. ------------------ Project 1970 - soon to be seen at http://milhouse.treylis.org:81/ __________________ Project1970 - LS1 Swap Complete!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.