[AldoNova67]

Did 65 use a POA valve or something else? is it necessary to adjust it for 134a? The adjustment seems so slight with the other years. Could I adjust later if needed. I’m keeping my A6 compressor because it’s practically new. I was using Ester already just in case I had to go with 134a. I’ll change all the orings. I had a little r12 left but didn’t get the job done. I blew out my hose right at the condenser. Pressure was low too. Weird. The belt started bouncing hard As well. My only thought is a blockage or too much oil. I’m assuming the POA is in some god forgotten area…lol
thanks guys!

 

[DUTCH MAX HEADWORK]

Any of this look faMILIAR? That thing on the left that looks like a space station is the POA evolve. Yes, that small adjustment makes a big difference. No, you can't do it later because the adjustment is done from the inside of the a/c tube. I've never worked on or really looked at the 65 a/c system.

You might try to find some r12, in order to have an efficient 134 system, you should upgrade the condenser to a parallel flow type. If not done, then you'll likely experience less cooling with the 134 than the original r12 system.

I don't recommend those degrading poa valve eliminator kits....junk.

This is the adjusting screw in a 70 poa valve.

This is listed as a 1965 66 67 Chevelle GTO - Evaporator & Housing Case Air Conditioning AC. Look familiar? Where's your space station?

 

[SSuper Dave]

Didn't the earlier cars use a suction throttling valve instead of a POA?

 

[DUTCH MAX HEADWORK]

Didn't the earlier cars use a suction throttling valve instead of a POA?

I think you are correct, I know jack about the 65 ac. It would look like this valve Aldo.
I'll take a WAG and say it's buried and the inner fender might need to be pulled for access. Original Air has rebuild list for those, Not sure if they can be adjusted for 134...learning with you.

A65 service manual will likely describe the system and service procedure....I no got. The 65 aim likely shows the parts and assembly, again, no got.

 

[swampy 6x6]

hi
If your R12 system has any barbed pipe connections [used with hose clamps ] these barbs do not play well with lined R134A HOSE . The barbs cut the liner and can cause slow leaks . R134a uses beadlock fittings . These can be purchased as weld on fittings.
R134a = parallel condenser , different grade drier Xh7 XH9 dessicant , elec condenser fans , heavy duty engine fluid drive fan , different hoses ,o rings ,compressor oil , TXV different , CCOT/orifice maybe

 

[AldoNova67]

Now that I’m completely overwhelmed in a good way, I thank you all for the input. Might be better off finding some r12 somewhere. Although I was kind of excited to make some custom barrier lines with a new condenser. I have some drinking, I mean thinking to do. Thanks again. If anything else comes to mind…fire it up!

 

[SSuper Dave]

I've used the barbed fittings with clamps on barrier hose without issue in the past, my '68 Caprice is going on 5 years with three of them on it.

 

[AldoNova67]

Perfect Dave, feeling more confident moving forward. I have my plan.

 

[AldoNova67]

Last question (that’s what they all say). Did the factory AC systems come with a binary safety switch?
if so, when converting to 134a, I’m thinking I shouldn’t have to change anything there.

 

[billdini]

Just to throw a twist into this conversation I use R12A in both my 68 Chevelle and my wife's 71 Camaro. I can use either oil with much less head pressure so when I engage the compressor it only drops 50 rpm so np need for a bump solenoid. However it is a flammable mixture (mostly propane) which is no more flammable then the latest R-1234. Cheap too if you decide you want to change to another coolant later and it is very environmentally friendly.

 

[AldoNova67]

Just to throw a twist into this conversation I use R12A in both my 68 Chevelle and my wife's 71 Camaro. I can use either oil with much less head pressure so when I engage the compressor it only drops 50 rpm so np need for a bump solenoid. However it is a flammable mixture (mostly propane) which is no more flammable then the latest R-1234. Cheap too if you decide you want to change to another coolant later and it is very environmentally friendly.

Some food for thought there. Do you know anything about my last question…binary switch? Thanks Bill

 

[billdini]

Some food for thought there. Do you know anything about my last question…binary switch? Thanks Bill

Binary switch no I don't. I do know you can't run oil for R134 with R12 coolant and vice versa. R12a can use the old or new Teflon seals which you should replace anyway. I bought it because I was planning to charge the system and make sure it held a charge for at least 3 month and then I was gonna drop 150 bucks and use R12. This stuff works better, its colder and uses much less refrigerant. I have decided to just stay with it. I bought this on Ebay for $42 bucks so shop.

R-12. R12, Artic Air, GET COLDER AIR, R12 Refrigerant support, Artic, 6 cans | eBay

Find many great new & used options and get the best deals for R-12. R12, Artic Air, GET COLDER AIR, R12 Refrigerant support, Artic, 6 cans at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[billdini]

Here is my last actual product I bought. You need to know how much refrigerant your system holds. IIRC each can is equivalent to 18 ounces of R12

ZeroR® Universal AC Refrigerant (3) 6oz Cans 16oz R134a Replacement Made in USA | eBay

COLDER THAN R134A & R12 – ZeroR AC Refrigerant is a lightweight gas and reduces friction in your AC system which improves cooling performance! Due to EPA regulations, we can not advise you to use this product in any system type except R134a despite it being chemically compatible with most...

www.ebay.com

 

[TC-CarGuy]

1964-65 Chevelle used a STV (Suction Throttling Valve). It's mounted behind the passenger-side fender-well, which a bunch of fittings that attach to it that extend into the engine compartment. Attached is a picture without the valve installed on it, but it attaches to the top fitting. The one shown in the photos above is a late 66-67. Unlike the POA valve, which as to be calibrated before installing it, the STV is calibrated by adjusting the vacuum actuator in/out. Right about 30psi on the low side for the old R12 or right about 20psi on the low side for 134a. You would typically charge between 70-80% of the original R12 charge amount.

 

[JohnC]

Here is my last actual product I bought. You need to know how much refrigerant your system holds. IIRC each can is equivalent to 18 ounces of R12

ZeroR® Universal AC Refrigerant (3) 6oz Cans 16oz R134a Replacement Made in USA | eBay

COLDER THAN R134A & R12 – ZeroR AC Refrigerant is a lightweight gas and reduces friction in your AC system which improves cooling performance! Due to EPA regulations, we can not advise you to use this product in any system type except R134a despite it being chemically compatible with most...

www.ebay.com

Hey Billdini, not familiar with that product. Is that new? Seems like it must not be traditional R12 because you can buy it easily and because it’s so cheap. Is it compatible with R12?

If one converts their car for 134a with a different condenser and decides (before it’s filled with 134a) to go R12, will it cool even better than the stock system?

 

[billdini]

John, it has a bunch of pluses with one negative. It is flammable! It can actually mix with R12 or R134 but it isn't legal to be mixed in the USA but it works and can be. However I never have. Its been selling for years in Germany and Canada with new cars.. It used to be sold as R12a but it now has been changed. I am assuming that you are talking about a parallel condenser. That will improve both R12 and R134 but it is mostly to cool R134 better. With that condenser and the POA adjusted for R134 it also works well but not quite as good. I am using R12a with new stock condensers in both my cars and it does work very well. It can also use either oil if you decide to go back to R12 or 134. You should change your hoses and seals if you are using an old R12 system although that is not a requirement with this stuff. The ads tell the truth, stuff works better then R12 or R134. BTW the new R1234 is also flammable but new cars are less likely to promote a spark especially the blower. However very little R12a (basically propane) is used in comparison with R12 or R134

 

[AldoNova67]

1964-65 Chevelle used a STV (Suction Throttling Valve). It's mounted behind the passenger-side fender-well, which a bunch of fittings that attach to it that extend into the engine compartment. Attached is a picture without the valve installed on it, but it attaches to the top fitting. The one shown in the photos above is a late 66-67. Unlike the POA valve, which as to be calibrated before installing it, the STV is calibrated by adjusting the vacuum actuator in/out. Right about 30psi on the low side for the old R12 or right about 20psi on the low side for 134a. You would typically charge between 70-80% of the original R12 charge amount.

Do you know how to adjust the STV vacuum actuator to 20psi for 134a? Would love to see a diagram but been searching with no luck. Companies offer to recalibrate the STV valve but it seems like I only need to adjust it….but how?
thanks