Adjusting stock POA for r134

[leddzepp]

Originally Posted by davepl

Weird that mine works with all original parts except the condenser, and even then I went parallel and not serpentine, so I guess that's "wrong" too.

My system blows 40F with R-134 and factory parts.

I think the notion that all of the factory parts are incompatible with R-134 flies in the face of the fact that mine works great.

Now granted I used all new "old" parts, so I don't have a bunch of the old oil, and I used green and grey o-rings. So it's never as simple as just filling the old system with R-134, of course. I also wound up with a new compressor because of leak at the snout, which is apparently common. Basically, if LMC Truck sells it, I installed a new one of it. But they're all reproductions of original parts, not "special" R-134 parts, so far as I can tell.

This thread in particular has a lot of doom and gloom and pounding the table about how what many of us are doing successfully absolutely cannot work.

I'm not telling anyone what to do. Just saying mine works great.

You don't live in the desert where temps hit triple digits. It might be a different story then.

[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 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.

[rsgt]

Here is mine. It is 93 out today. Sitting out in the yard idling I got 42 in the center vent. When I bought my truck the compressor was in the bed of the truck. I flushed the lines, replaced the dryer and expansion valve, bought an aluminum replacement compressor. I bought R12 at a swap meet for $20.00 a can.

[Rufas]

Originally Posted by rsgt

Here is mine. It is 93 out today. Sitting out in the yard idling I got 42 in the center vent. When I bought my truck the compressor was in the bed of the truck. I flushed the lines, replaced the dryer and expansion valve, bought an aluminum replacement compressor. I bought R12 at a swap meet for $20.00 a can.

I know this is totally off topic.

I saw a recent FamtomWorks on Velocity. They charged a customer $1,500 per can of R12!!!!

Oh well back to the main topic.

[F.A.A.benny]

I used to work for them l, Andy. On my first day there that's where they put. Rebuilding poa valves

[engineer_gregh]

I bought 12oz. cans of 134a on clearance at Big Lots for $2.00 each, I live right outside Nashville TN; Yea I bought two cases at that price. Normal prices here average $5 a can if you shop around. The biggest rip off is the larger cans with the hose and gauge for $39.95, you're pretty much guaranteed to screw up you A/C system with it and you pay more for the privilege. R12 will cost you $30-$50 a can, if you can find it. And yes there are EPA restrictions selling or purchasing R12.

[engineer_gregh]

Another note; the oil used for R12 and R134a are not compatible! There are hack shops out there that will evacuate an R12 system and charge with R134a. That will absolutely fail, period, no question. With just evacuating a system you still have oil left in the compressor. Senior members on this board have suffered the bumps and bruises, and paid the cost to learn these things. Guys like leddzepp, Andy, Dave, and numerous others are nice enough to share their experiences, much appreciated guys. And just in case you hadn't noticed they can get pretty passionate about their trucks! Just do your homework and ask questions on this board and you will get the answers you need to get your truck in the desired condition you seek.

[Andy4639]

Originally Posted by engineer_gregh

Another note; the oil used for R12 and R134a are not compatible! There are hack shops out there that will evacuate an R12 system and charge with R134a. That will absolutely fail, period, no question. With just evacuating a system you still have oil left in the compressor. Senior members on this board have suffered the bumps and bruises, and paid the cost to learn these things. Guys like leddzepp, Andy, Dave, and numerous others are nice enough to share their experiences, much appreciated guys. And just in case you hadn't noticed they can get pretty passionate about their trucks! Just do your homework and ask questions on this board and you will get the answers you need to get your truck in the desired condition you seek.

Thanks,
I try and help people all I can. We all learn from each other.
Another note that a lot of people may are may not know. A good AC shop guy will want to know if your system is R-12 are 134-A before they do anything to it. The recovery machines can only do one are the other. They can't mix the 2 together. I have had some even tell me they don't want the synthetic stuff either in their machines like you buy at the parts stores. 134-A freeze and AC Pro.
I took both my 71 and Impala to my guy who charges me $50.00 to vacuum and charge the system. He only uses 134-A no synthetic stuff. I had to take the truck stuff a part this past spring and flush out the system because the 20 year old accumulator desiccant had failed and clogged up my orifice tube.
The Impala was a first time job.

[ApacheIvan]

Originally Posted by engineer_gregh

Another note; the oil used for R12 and R134a are not compatible! There are hack shops out there that will evacuate an R12 system and charge with R134a. That will absolutely fail, period, no question. With just evacuating a system you still have oil left in the compressor. Senior members on this board have suffered the bumps and bruises, and paid the cost to learn these things. Guys like leddzepp, Andy, Dave, and numerous others are nice enough to share their experiences, much appreciated guys. And just in case you hadn't noticed they can get pretty passionate about their trucks! Just do your homework and ask questions on this board and you will get the answers you need to get your truck in the desired condition you seek.

I think I am just going to buy the right R12 hose for the compressor, evacuate and flush the r134 out and put R12 back in it. I spent too much money for all the OEM stock components to switch it all out, I could adjust the POA and "hope" it works with the possibility of not being happy..and just have to do it again. I only have one component in the system that cost about 100 bucks to replace to make it so. Not looking forward to the cost of the R12 or taking it all back apart to get all the old oil out of it, but if I want cold air I guess I have to Everything I read says 3.25 lbs (right around 52oz if my math is correct) and 8oz of oil. Fun!

[leddzepp]

I think the thing EVERYONE who has done AC work can agree on is that you do NOT use synthetics, additives, or "stop leak". That stuff is proprietary crap that will ruin a system. R-12 or R-134 only, nothing fancy. No AC shop will touch a system that has anything other than freon used. When I see someone in line at the store with some of those "fancy" freon cans I just shake my head.

[Bigdav160]

Isn't PAG synthetic oil? It is the only oil recommended by the OE. They warn about using esters.

[mrein3]

I converted a non-AC cab to AC with factory parts. I did a write up about it here:
http://67-72chevytrucks.com/vboard/s...d.php?t=478564

The adjust POA link no longer works. Sorry about that. I did adjust mine and it works good. You can always adjust it back and run R12.

[F.A.A.benny]

You can put an adaptor fitting on the muffler manifold. I'd replace the hoses but there are those that do not. I'd really consider changing them if the fittings were clamped instead of crimped

[engineer_gregh]

My comments (in italics) on Tony's earlier post are based on my own experience in rebuilding the A/C on my 71 money pit. It blows 42 degrees with R134a.

Just for (*&()^, from my education to-date, this identifies the system and what's required for 134a conversion. Corrections welcome:

Original Evaporator: Works for R12 & R134a

Original Expansion valve: Works for R12 & R134a

Original POA valve: Works for R12 & R134a, though must be calibrated for what you're using.

Original Muffler: Does not work for R134a. Not true, it can be used with an adapter. R12 and R134a use different fittings for servicing.

Original hoses: Word is the original hoses do not work for R134a. Un-confirmed. Not true, but if your hoses are terminated with clamps versus crimped you should change them. If they are original and 40+ years old I would change them.

Original compressor: Works for R12 & R134a

Original O-rings: Do not work for R134a. Not true

Original Dryer: Does not work for R134a. Not true, but a new one at Auto Zone is $12.99 so change it.

Original Condenser: Works for R134a, but not as well as serpentine replacements, which remove heat better. The original condensers are tubed. I believe you meant parallel flow not serpentine. 100% correct although if you add pusher fans to the tubed typed condenser it helps in dissipating the heat.
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[71CHEVYSHORTBED402]

Originally Posted by engineer_gregh

My comments (in italics) on Tony's earlier post are based on my own experience in rebuilding the A/C on my 71 money pit. It blows 42 degrees with R134a.

Just for (*&()^, from my education to-date, this identifies the system and what's required for 134a conversion. Corrections welcome:

Original Evaporator: Works for R12 & R134a

Original Expansion valve: Works for R12 & R134a

Original POA valve: Works for R12 & R134a, though must be calibrated for what you're using.

Original Muffler: Does not work for R134a. Not true, it can be used with an adapter. R12 and R134a use different fittings for servicing.

Original hoses: Word is the original hoses do not work for R134a. Un-confirmed. Not true, but if your hoses are terminated with clamps versus crimped you should change them. If they are original and 40+ years old I would change them.

Original compressor: Works for R12 & R134a

Original O-rings: Do not work for R134a. Not true

Original Dryer: Does not work for R134a. Not true, but a new one at Auto Zone is $12.99 so change it.

Original Condenser: Works for R134a, but not as well as serpentine replacements, which remove heat better. The original condensers are tubed. I believe you meant parallel flow not serpentine. 100% correct although if you add pusher fans to the tubed typed condenser it helps in dissipating the heat.
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Thank you. I'd heard the dryer wasn't compatible. I don't remember who told me that, but I recall they being a good source. Doesn't mean they're right. Might also mean yeah it works, but for some reason, not as well long term. I have an NOS dryer, which adds some interest.

Surprised to hear O-rings are compatible. Perhaps I mistook "replace them anyway" with "doesn't work". Then again, might be another case of longevity.

Personally, I'm hoping a guy restores behind the muffler. It's not cheap, but the comfort knowing it's first rate is a nice option. I'm using 134a. Honestly, I'm good with the windows & vents open. Something to be said for having A/C when you need it, never mind everything works.

Though my muffler looks like new, and the adapter sounds great, like you say, the hoses (crimped) are pushing five decades. So new muffler & hoses.

Rebuilt compressor. And decal - I guess.

Dryer appears to be up in the air.

My condenser is thrashed. I'll get what works & mounts best......hopefully.

[anew4961]

I put r12 back in mine and it cools down to 38 degrees at idle what's better than that

[ApacheIvan]

Originally Posted by anew4961

I put r12 back in mine and it cools down to 38 degrees at idle what's better than that

Did you do it yourself? What all did you have to do to accomplish that and what was the final cost?

[anew4961]

Originally Posted by ApacheIvan

Did you do it yourself? What all did you have to do to accomplish that and what was the final cost?

everything is original except compressor ,lines and updated poa valve I flushed and cleaned the system with brake clean then flushed with water then blowed it dry with compressed air drained new compressor of oil put new oil in compressor filled with R12 I worked on transport referigation with compressor and other parts around 4 o 5 hundred dollars I was smart years ago and kept 3 30 lb. tanks of r12

[ApacheIvan]

Originally Posted by anew4961

everything is original except compressor ,lines and updated poa valve I flushed and cleaned the system with brake clean then flushed with water then blowed it dry with compressed air drained new compressor of oil put new oil in compressor filled with R12 I worked on transport referigation with compressor and other parts around 4 o 5 hundred dollars I was smart years ago and kept 3 30 lb. tanks of r12

What is updated on your POA?

[davischevy]

I have to smile when I read this thread. I bought a 1972 Cheyenne new, and almost from day one there have been arguments about whether the AC worked well on them.

[F.A.A.benny]

Originally Posted by ApacheIvan

What is updated on your POA?

He is refering to a poa delete kit which is essentially just a tube with a cycling switch on it. If your poa valve is good you should stick with that.

[Bigdav160]

The old XH-5 desiccant in the drier is not compatible with R134a. The pore size is wrong and the R134a/pag will slowly disolve the desiccant.

XH-7 is the preferred desiccant for R134a and should work for R12 also. Many companies are using XH-9 desiccant universally but XH-7 is still used in better brands.