Adjusting stock POA for r134

[ApacheIvan]

I have all new AC in my 72. Everything is new except for evaporator and POA. New compressor, new hoses, new evaporator and expansion valve. When I bought the new hose with muffler on it I opted to go r134 so it has the proper valve in it already, converted the valve on the POA. With that said, I had it professionally charged. I was told since everything was stock that I should have had my POA pressure adjusted to get optimum cooling. Now that it all works, it blows cool but nor really cold. I hate that I have to evacuate the system again and take the POA out. Vintage Air is telling me I should get the kit that eliminates the POA and cycles the compressor. I don't like that idea, I would like it to look as stock as possible. Someone told me there was a guy on the forums that will service the POA for me but could not recall who it was. I did some searches but could not find him. If it is easy to do, I suppose I can do it myself, but don't have an air compressor at the moment.. so I am open to any and all suggestions.

[leddzepp]

Get rid of the 134 and go back to r-12. Your factory system will never function properly with r-134. I've gone through this many times....

[ApacheIvan]

Originally Posted by leddzepp

Get rid of the 134 and go back to r-12. Your factory system will never function properly with r-134. I've gone through this many times....

I have heard that too.. ugh.. expensive I will have to get a new muffler with the right fitting and pay a pretty penny for r12.. I may just do that..Learning from someone who has already spent the money

[ss454conv]

Going to R12 will be the best and freeze you out but I had a system in a Chevelle with 134 and an adjusted POA valve and it worked really well. I would say it was almost as good as my buddy's R12 system. For 134 to work well in an original system the POA needs to be adjusted, you need a A-10 compressor(A-6 will leak at the front seal) and a duel pass condenser.
I did not have the other two, only the POA and it was still good.
Good luck.

[Andy4639]

134-A will cool as good as any R-12 system ever would. If you do the system right and don't cut corners it will cool better. The POA valve may be the part that keeps the 134-A from cooling down and this is why they say replace it.
If it where me I would replace it and be done. If you keep it then go back to R-12.
134-A done right will cool as good are better than R-12! I have done my 71 C10, 64 SS Impala and the 56 Bel Air all in 134-A and it works great you just have to do it correctly.
As far as looking correct well most people (generally speaking) have no idea what they are looking at under a hood of a vehicle most of the time.

Lets see some tempatures of all these R-12 systems that are freezing cold guy's.

My C10:





The Impala:

[engineer_gregh]

You need to talk with F.A.A Benny. He is on the forum and can adjust your POA valve. As leddzepp said R12 is best but 134a will work with a lot of changes. A parallel flow condenser or at least one to two pusher fans on a standard condenser is required. I just rebuilt mine and have a pretty detailed thread on the subject. Andy above is also correct but notice all the changes he has made; he has installed a modern compressor, replaced his POA and expansion valve with an accumulator, pressure switch, and orifice tube and is running a parallel flow condenser.

[ApacheIvan]

Originally Posted by Andy4639

134-A will cool as good as any R-12 system ever would. If you do the system right and don't cut corners it will cool better. The POA valve may be the part that keeps the 134-A from cooling down and this is why they say replace it.
If it where me I would replace it and be done. If you keep it then go back to R-12.
134-A done right will cool as good are better than R-12! I have done my 71 C10, 64 SS Impala and the 56 Bel Air all in 134-A and it works great you just have to do it correctly.
As far as looking correct well most people (generally speaking) have no idea what they are looking at under a hood of a vehicle most of the time.

Lets see some tempatures of all these R-12 systems that are freezing cold guy's.

Ugh, I just spent 1000 dollars doing it right, but I guess I did it right for R12 because it is all stock. Everything under the hood is brand new. When you say most people don't know the difference, you mean anyone who doesn't know our trucks or Chevys for that matter. I guess I should't care if I want cold air

[engineer_gregh]

F.A.A Benny is in TX, not sure which city. You can private message him and I'm sure he will respond. He restores AC systems for a lot of different vehicles. His work is top notch! Now that I went through your build thread, I completely understand why you want to keep it original. Keep it R12, just my .02 cents.

[ApacheIvan]

Originally Posted by engineer_gregh

F.A.A Benny is in TX, not sure which city. You can private message him and I'm sure he will respond. He restores AC systems for a lot of different vehicles. His work is top notch! Now that I went through your build thread, I completely understand why you want to keep it original. Keep it R12, just my .02 cents.

Thanks for the heads up, that is exactly what I am doing, He does not live far from me either and if he can do the evacuation and recharge the better. I will just take him the truck. And yeah, it has huge sentimental value and needs to be just like it was when dad bought it. He has been off this earth now 20 years this year and I vowed to restore it to it's full glory. Interestingly enough his other baby which I am looking for is a 1964 Chevy Impala SS that was his first new car and one that was stolen out of his driveway in the mid 80s. That is the only thing on my bucketlist that I have not found yet

Thanks again for taking the time and pointing me in the right direction.

[leddzepp]

Originally Posted by engineer_gregh

Andy above is also correct but notice all the changes he has made; he has installed a modern compressor, replaced his POA and expansion valve with an accumulator, pressure switch, and orifice tube and is running a parallel flow condenser.

Exactly!

Every time I post about r-12 being superior to r-134 in a FACTORY system he goes on about how it isn't...yet his system isn't factory anymore...which is my point! I have no doubt it works; it better after spending $1200 on the changes.

[Andy4639]

It is factory looking!

It was 134-A with all internals for a 71 when I did it the first time. It did fine but I knew it could do better and that's when I swapped everything out.
Back when I did the AC the first time though nobody was doing the POA valves so it would cool but not like it does now. When I did do the swap it was easier to just swap it out for the newer stuff.

ApacheIvan
When you say most people don't know the difference, you mean anyone who doesn't know our trucks or Chevys for that matter. I guess I should't care if I want cold air

Yes that was what I meant by the general public.
Unless you are going for 100 point show vehicle why worry what is factory are not, If you drive it like I do then comfort is what I go for.

Here are a couple of pictures of the SS for you also. By the way the SS has the A-6 compressor in it. It runs fine so far but it just got charged up this past winter so time will tell.

[Andy4639]

Originally Posted by leddzepp

Exactly!

Every time I post about r-12 being superior to r-134 in a FACTORY system he goes on about how it isn't...yet his system isn't factory anymore...which is my point! I have no doubt it works; it better after spending $1200 on the changes.

I have less than that in the whole system with the swap. But ok you got me on this. It isn't factory internally but what most people see is a factory unit. Because most don't know.

[davepl]

Originally Posted by leddzepp

Get rid of the 134 and go back to r-12. Your factory system will never function properly with r-134. I've gone through this many times....

You have, at which point I normally chime in to say that (with a parallel flow condenser) my factory system works AWESOME with R-134.

It's entirely possible the PO made changes or adjustments to the POA valve, as it already had the 134 fittings when I got the truck. But it's stock pieces so far as I can tell, except the condenser as noted. Oh and I suppose I should admit that I changed the compressor later, but that was for a leak. So I'll go with "stock appearing" R-134 and you can be "actually stock" R-12.

So I reject your theory! R-134 is the solution to every problem! With suitable disclaimers attached!

That said, if I had a functioning R-12 system that I was sure wasn't going to leak that pricey stuff back out, I'd just stick with R-12 myself. But if I wasn't sure, I'd rather leak R-134 than R-12.

[Low Elco]

PM ls1nova71 on here. He has 2 of these trucks that look dead stock and blow icebergs. I believe he uses the biggest parallel flow condenser he can get and switches to a squarebody unit in the cab box. IDK, i just know it works and how!

[Andy4639]

My 64 SS Impala blows at 36* with a stock system. When I bought it the guy had done the 134-A swap but it wasn't working. I redid the lines and got it back in shape. It has been fine all summer so far.
I added the longer lines to hide them inside the fender and a new dryer. Vacuumed and charged it.
As I have stated before if done right doesn't matter which Freon you use. Getting 40 year old fittings to seal off is the hardest part to do.

[Big Block]

Ok guy's this is all new to me. Just bought a 71 Chevy Custom Deluxe Short Bed with factor air. It appears to be intact and complete. The previous owner did a new heater core. It has the original compressor on it but the system is empty and the compressor won't engage. I have a factory style replacement compressor. Should I replace the receiver, dryer, and compressor and pull a vacuum to see if it holds. If it does hold a charge, would you go ahead and charge it with r12. Or just replace everything first and upgrade everything to 134. The system hasn't worked for over 20 years.

[notsolo]

As long as were beating this to death! Whats the going rate for R12?....If you know somebody you might get a deal, 15 yrs ago local shop here was charging $400.00.to evacuate and charge.....I changed and charged my 93 over to 134a for $165.00 no regrets....I'm not the purest, I like the modern engine and 1 belt....If you like keeping it total stock, Excellent, its your boat.

[leddzepp]

I can buy r12 on craigslist for LESS than r134 at autozone here, so the cost savings is a myth.

I really don't care what anyone does with their ac system, I post what works and I have cold air in ANY condition.

If people want to run around the block 6 times chasing cold air, throwing money at what might work or work marginally, that's fine. I'll just hit the easy button and walk next door.

[ApacheIvan]

I am going to leave it to Benny I have a PM to him waiting a reply.. I live within 30 miles of him, and instead of figuring it out myself, paying for multiple charges and taking things apart and "trying" out a bunch of stuff, I will leave it to the expert When I am done it will look stock, if he recommends r12 I will hit eBay, (surprised it is not a restricted buy) if he can get it cold with r134 for this Texas heat, then I will post my report after we are done if he will help me

[tdangle]

Originally Posted by leddzepp

I can buy r12 on craigslist for LESS than r134 at autozone here, so the cost savings is a myth.

I really don't care what anyone does with their ac system, I post what works and I have cold air in ANY condition.

If people want to run around the block 6 times chasing cold air, throwing money at what might work or work marginally, that's fine. I'll just hit the easy button and walk next door.

Now that I've fixed the leaks in my system, I would love to switch back to R12. As Leddzepp says without a bunch of work and mods, imo, R134 doesn't work as well. Cool but not super cold like my DD (15 Challenger Hemi RT). Best I can find on CL is about $35 a 12 oz can. Although not cheaper than Autozone R134 where I just bought at 2 12oz cans for $20. I'll just keep on looking.

[F.A.A.benny]

I don't think anyone can beat Wal-Mart price on 134a.https://www.walmart.com/ip/Super-Tec...134a/617476716

[leddzepp]

R134 is $5 a can in Vegas, I buy a case every time I visit. I use 134 in all of my newer cars because that's what they are DESIGNED for and it works like it should.

[F.A.A.benny]

Originally Posted by Big Block

Ok guy's this is all new to me. Just bought a 71 Chevy Custom Deluxe Short Bed with factor air. It appears to be intact and complete. The previous owner did a new heater core. It has the original compressor on it but the system is empty and the compressor won't engage. I have a factory style replacement compressor. Should I replace the receiver, dryer, and compressor and pull a vacuum to see if it holds. If it does hold a charge, would you go ahead and charge it with r12. Or just replace everything first and upgrade everything to 134. The system hasn't worked for over 20 years.

I'd be worried about there being an issue with the poa valve. If its stuck, you wouldn't know it just by holding a vacuum

[F.A.A.benny]

Originally Posted by leddzepp

R134 is $5 a can in Vegas, I buy a case every time I visit. I use 134 in all of my newer cars because that's what they are DESIGNED for and it works like it should.

Wal-Mart doesn't sell 134@ at 5 can in California?

[leddzepp]

Originally Posted by F.A.A.benny

Wal-Mart doesn't sell 134@ at 5 can in California?

It's at least $10 a can here with a $10 deposit on each can on top of that. You get the deposit back only if you return the used can within 30 days. They also have a "new" style dispenser on them that is California only. This is why I have stockpiled both 12 and 134 for years now, it's only a matter of time before do it yourself AC will no longer be an option...then everyone will be forced to pay a fortune to have a shop do the work.