High and Low side a/c

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93ragtop said:

The 134a for commercial refrigeration is a different drum..... Below is a picture of the one I have currently.
BTW I just called my supplier and its $110.00 a drum.

View attachment 1715581100
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That's weird. The jug I bought came from "North 40". I have not kept up, there has been talk of requiring license for large amounts larger than the 12oz cans
 
Yes, I dont know why they did it that way, other then commercial refrigeration guys tend to work with several different refrigerants.....
I believe the intent with automotive was of course not to mix the two. R12 and R134a.
 
67Dart273 said:
The 134 "jug" I bought (30lb) is NOT standard 1/4 flare. It is some special "new" fitting and required an adapter. The first one I bought off ebay did not fit. I don't know if it was the incorrect fitting, or just threaded wrong by the guy in the backyard shed in China. I don't know if some are different. "It would seem" that 134A would be "standardized" LOL

This is the adapter I needed and got 2nd try. What I needed was 1/2" Acme female (for the jug) and 1/4 male SAE (for the hoses/ manifold)

https://www.ebay.com/itm/New-FJC-6015-Air-Conditioning-R134A-1-2-Female-to-1-4-R12-Male-Flare-Adapter/183328909165?hash=item2aaf41276d:g:DLEAAOSwR0hbTOzu

View attachment 1715581098
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Yup. That's the same adapter I use.
 
I still use my old R22 / R12 gauges to charge my 69 with R134. I just took an R12 hose and a R134 hose, cut them in half and spliced a R12 half to a R134 half with a brass barbed hose splicer. I use this hose to hook up a R134 can tap to my R12 gauges. Now I can put $5 Walmart R134 in through my R12 gauges. No adapters needed on the car.

Poor people have poor ways.....
 
Mike69cuda said:
I still use my old R22 / R12 gauges to charge my 69 with R134. I just took an R12 hose and a R134 hose, cut them in half and spliced a R12 half to a R134 half with a brass barbed hose splicer. I use this hose to hook up a R134 can tap to my R12 gauges. Now I can put $5 Walmart R134 in through my R12 gauges. No adapters needed on the car.

Poor people have poor ways.....
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You didn't need to do that. I just screwed an R134A to R12 adapter to the manifold center port, than hooked a "quick connect" can and hose to that. But you are right "poor people"
 
SixgunSal said:
Yes I am really new to automotive A/C, this and brakes I never really tried. I have ordered a receiver drier and will try an automotive shop tomorrow to see if I can schedule a vacuum for the dart. Would I have a vacuum done before or after installing the new receiver drier? The salesman at Autozone suggested the Pagoil
so that what I have but have not put in in yet. I'm pretty sure the vacuum and manifold gage hose set were not the best for me trying this out...not trying to make excuses, but some stuff is better left to the pros and I know I'm not one of them. lol Thanks for the good advice and it's a relief not to be banging my head against the wall another day (what they say about old dogs and new tricks sounds pretty good thou).
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Hi,
You would install the new receiver/drier before you vacuum down the system. But, you first need to learn how to install A/C components and deal with the O ring seals. Sales people at places like Autozone are often not the best places to get advice. You don't know what type of oil or how much is currently in the system. PAG oil does not mix with R-12 mineral oil if that's what's in there now. It will form a kind of sludge. Also, adding more oil to what may already be in there will lead to too much oil in the system which causes other problems. So, it would be good to slow down, step back a bit and read the shop manual on oil quantity and how to measure it in an RV-2 compressor. PAG oil is also available in different viscosities and off hand I don't know what you would use in an RV-2. I use a polyester based oil for R-134A or 525 mineral oil for R-12

For now don't get sidetracked by discussions on how to charge the system, that comes later. The safest way for someone new to A/C work is to charge the system by gas through the low side service port. You will not run the risk of damaging anything this way.
 
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67Dart273 said:
You didn't need to do that. I just screwed an R134A to R12 adapter to the manifold center port, than hooked a "quick connect" can and hose to that. But you are right "poor people"
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Wow, I never thought of using the R134/R12 adapter on the gas hose. That would have been easier, even for the lazy poor guy.
 
Pete in NH said:
Hi,
You would install the new receiver/drier before you vacuum down the system. But, you first need to learn how to install A/C components and deal with the O ring seals. Sales people at places like Autozone are often not the best places to get advice. You don't know what type of oil or how much is currently in the system. PAG oil does not mix with R-12 mineral oil if that's what's in there now. It will form a kind of sludge. Also, adding more oil to what may already be in there will lead to too much oil in the system which causes other problems. So, it would be good to slow down, step back a bit and read the shop manual on oil quantity and how to measure it in an RV-2 compressor. PAG oil is also available in different viscosities and off hand I don't know what you would use in an RV-2. I use a polyester based oil for R-134A or 525 mineral oil for R-12

For now don't get sidetracked by discussions on how to charge the system, that comes later. The safest way for someone new to A/C work is to charge the system by gas through the low side service port. You will not run the risk of damaging anything this way.
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While we are talking about oil, doesn't the RV-2 compressors have their own crankcase and the oil never leaves the compressor or enters the freon system?
 
toolmanmike said:
While we are talking about oil, doesn't the RV-2 compressors have their own crankcase and the oil never leaves the compressor or enters the freon system?
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Yes, the RV-2 differs from more modern compressors in that they have their own oil sump and oil pump that provides internal pressure lubrication. They are one of the most rugged A/C compressors ever put on a car. They make great off road air compressors. They do however circulate a small amount of oil in the refrigerant. I suspect this is to keep the compressor reed valves happy and the expansion and EPR valves moving. If you use one as an off road air source you will have some oil along with your air and need to keep the compressor sump filled with oil and check it regularly. About the only thing that will kill an RV-2 is no oil.
 
Pete in NH said:
I like to use an ester based oil with is compatible with both R-12 and R-134A. You will also need to change the receiver /drier to and R-134A compatible type. All new receiver/driers today are both R-12 and R-134 A compatible. If you don't do this the R-134A will bust the old desiccant bag in the drier and spread desiccant through out the system and you'll have a real mess. 15 inches of vacuum is no where low enough and some thing is not right some where. A good tight system will easily get down to 28 inches and hold that vacuum for many hours. You are not anywhere near being able to recharge your system and get good results when done. Good A/C work requires attention to detail, it's not hard to do but short cuts will only get you in expensive trouble.
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Good advice here on the oil. Ester oil is common the the chain auto part stores around here. The FSM has the info for making a dip stick for the RV2 compressor. Good post, worth posting again. Post above, 34 spot on also. Thank you Pete.
 
I don't believe there is a compressor made that doesn't put some oil into the system
 
I know its been a few days on this but I wanted to thank everyone for the great advice regarding this problem i had with the darts a/c. After wasting over a week fooling with this, I took the advice to take it to a pro. They were able to pull a vacuum down to 29.3 which i never came close to. But I can report it now works, blowing way cooler then it was. Thanks again for you help and putting up with this old mans not so intelligent questions. :thumbsup:
 
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