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Rumor has it, I'm about 2 weeks away from finally having an engine to install into my '69 442. That being said, I probably should get all the loose ends tied up. One of which is to replace the AC line I busted. I can do that, but it then leads to my next question of recharging the system. I've never dealt with AC systems before, but know enough to know that while I'm fairly certain it has not been switched over already, it will most likely need converted over to R-134 as R-12 is now no longer available (so I'm told)
What all is involved in switching over to R-134? Is it something I can do at the house, or something better left to the shop while they install the engine?
Look on the charging ports. The 134a charging fittings are different than R12 and if done correctly should have blue and red caps.
If system has been open for any length of time it should be flushed and all fitting O-rings replaced anyway, and a new filter-drier is a must.
If you decide to convert to 134a you should get a POV valve that's calibrated for 134a, and either upgrade the condenser or install an electric pusher fan to improve airflow across the condenser while idling or stuck in slow traffic.
You can buy R12. It's isn't outrageously priced like it was years ago. In fact, I wouldn't be surprised if aftermarket manufacturers like Vintage Air phase out R134a before too long. New cars use R1234yf. It's "SUPPOSED" to be better for the manufacturer's walle... I mean the environment.
Look on the charging ports. The 134a charging fittings are different than R12 and if done correctly should have blue and red caps.
If system has been open for any length of time it should be flushed and all fitting O-rings replaced anyway, and a new filter-drier is a must.
If you decide to convert to 134a you should get a POV valve that's calibrated for 134a, and either upgrade the condenser or install an electric pusher fan to improve airflow across the condenser while idling or stuck in slow traffic.
My ignorance is showing, but is the dryer the canister looking thing up next to the condenser? Also, considering the line got busted and everything kind of exploded out of the line..do I assume there's still anything in there? Since the line busted, it's essentially been open the entire time as I've yet to get the line changed out yet. Regarding fitting o-rings, would that just be where the two main lines hook up? I probably could get that figured out when I get home and pull the manual out, but now I'm curious and stuck at work, ha!
Yes, that is the dryer.
Since the ac system has open for awhile, and if ac is important, I suggest servicing and possibly overhauling the entire system, trying to piece together an ac unit is a fool’s errand…
Replace every o ring. Throughly inspect everything. Replace anything questionable, without a doubt replace the dryer. If you have gauges, rent a vacuum pump to evacuate the system. Let the pump run for at least a half hour, then close the valves at let the car sit. If it holds vacuum overnight you can be reasonably sure there are no leaks.
Keep in mind the dryer won’t fit without modifying the mounting brackets, not a big deal. The original dryer is approx 10” x 3 1/2”.
I guess I hadn't paid that close attention to how it mounts. Are the brackets not separate (i.e. mounting a coil)
Other than that though, am I correct in seeing that kit has everything I need to both rebuild the AC system back to where it needs to be, as well as convert it to R134? Again, to my knowledge everything worked fine until I busted one of the lines (which I have a new line already)
Hmm. That kit has a new expansion valve, but no POA valve? I thought converting to R134A entailed recalibrating the POA valve and using the original expansion valve, but then again I opted to keep using R12 instead of converting to R134A so I don't have first-hand experience with this.
If you decide to convert to 134a you should get a POV valve that's calibrated for 134a, and either upgrade the condenser or install an electric pusher fan to improve airflow across the condenser while idling or stuck in slow traffic.
Originally Posted by Fun71
Hmm. That kit has a new expansion valve, but no POA valve?
x3
What about the POA valve? FWIW, I converted the AC in a 90 Buick Estate Wagon from R12 to R134a. All I did was replace the orifice tube and lines (newer system). I didn't change the condenser. It never cooled well with R134a. Make sure you do the conversion correctly, or just get an aftermarket Vintage Air system designed for R134a.
I had better luck converting a 1981 Pontiac Safari and a 1983 Custom Cruiser. Both would blow 38° at the center vent with 90° ambient unless you were stuck in slow traffic. It did good to reach 55° in those conditions.
But the CSM performance charts indicated 55° in 90° ambient was considered acceptable.
A few things to consider. There is still oil in your sytem. The oil does not just blow out with the refrigerant when the system is open. To remove it, you really need to take each component off (evaperator, condensor, compressor, and lines) and allow them to drain out for a few days followed by a flush. Some of the old R12 oils are not compatible with 134 and can gum up. Also, if you simply add more oil to the system you can get it too full which can cause other issues. There is a sticky in the general discussion section about calibrating the POA valve yourself:
It is an r12 replacement and is supposed to work in the factory system as is. I still replaced my expansion valve, dryer and all of the o-rings but I will leave the POA valve calibration alone. Once I get it charged (still a few weeks away from that) I will report back with how well it works. By the way, a factory style dryer is pretty cheap Here is the one I got for my car and you can find them cheaper than this on Amazon (didn't realize that until after I got the one in the link):
brotherGood, everything above covers your a/c system, however you haven’t checked your compressor to see if it still turns.
Im in the process of refurbishing my entire system, new: condenser, parallel flow evaporator, expansion valve, dryer and a new style billet POA valve, I have a Pro6Ten compressor, in place of an A6, I’m hoping it will get cold with R-134
Last edited by dc2x4drvr; July 12th, 2022 at 03:13 PM.
No..but I figured since I already need to replace the line that busted, as well as the dryer since it's been open..it'd make sense to bite the bullet long term.
Ultimately, I don't care what's in it as long as it works. I do know though that the goal is for it to get done either by, or while the car goes in for the engine install (which should be soon). So at the very least if I get the parts in, it may help.
The replacement line and drier don’t care what refrigerant you will use. The only thing that will really matter is the type of oil.
i agree, my concern was just for the sake of going ahead and getting it done due to the fact R12 is (or it was my understanding that) no longer available.
i agree, my concern was just for the sake of going ahead and getting it done due to the fact R12 is (or it was my understanding that) no longer available.
R12 is available, if you know where to get it (most AC shops should have a supply). FWIW, I used this R12a in the system of my 86 Ford F250 and it worked well. At the time, I bought it on Amazon. It's supposed to be a direct replacement for R12. Eventually, all the refrigerant leaked out of the system in my truck (a year or two later). Even though I tried to charge it again it didn't blow cold.
If I were to get the AC working in my truck again I would flush all the components, replace the lines and charge it with R12a before I considered R134a.
there are 16 ounces in a pound, there should be a data tag/label usually on the evaporator housing that states the amount of refrigerant charge, usually it is in pounds or ounces. I would have to look at mine to tell you what it is exactly.
On your 69, the tag will be on the compressor. It looks something like this. most gm sytems from that era use 4 - 4.5 lbs. This only applies if you are using r12. there is a conversion factor if you replace with 134 as the system will use less.
Here you can see the sticker on my Toronado compressor.
Last edited by Loaded68W34; July 13th, 2022 at 02:34 PM.
A few things to consider. There is still oil in your sytem. The oil does not just blow out with the refrigerant when the system is open. To remove it, you really need to take each component off (evaperator, condensor, compressor, and lines) and allow them to drain out for a few days followed by a flush. Some of the old R12 oils are not compatible with 134 and can gum up. Also, if you simply add more oil to the system you can get it too full which can cause other issues. There is a sticky in the general discussion section about calibrating the POA valve yourself:
It is an r12 replacement and is supposed to work in the factory system as is. I still replaced my expansion valve, dryer and all of the o-rings but I will leave the POA valve calibration alone. Once I get it charged (still a few weeks away from that) I will report back with how well it works. By the way, a factory style dryer is pretty cheap Here is the one I got for my car and you can find them cheaper than this on Amazon (didn't realize that until after I got the one in the link):
I see R12 at every swap, my neighbor has a stash he’s selling it’s not hard to find. At my cars and coffee, I think he sold it all I bought a 30lb tank.
the GM oil there I just bought at the Packard swap.
No word yet. I have not pruchased it yet because the car is still going together. Here is a close to current photo. Since this pic, the right side stripes are done, the fender and door are buffed and the inner fender is in.
July 7th, 2022, 11:32 AM
