AC recharge

[Haynesie]

just needs a recharge, how do i do it?

 

[trbodon21]

Have you already converted to the R134. If so go to your local parts store and pick up a recharge kit. Usually comes with a gauge to check the pressure of the refrigerant, which indicates how much is left and then a 12 oz bottle of the refrigerant. Just hook up the supplied hose to the refrigerant bottle and the other end to the port at the AC canister that has a blue cap on it. ONce it is hooked up open the valve on the refrigerant and let it charge. Check to see what pressure your at with the gauge. The kit usually tells you around what pressure it should be.

 

[VernLee]

Turbodon21, I'am going to change to R134 Do I have to change the oil in my compresser ? and if so, whats the best method to do so, thanks
Vern

 

[trbodon21]

I believe there is a retro kit for converting to 134A. I think it has the oil your talking about. The only thing you have to consider is getting rid of the R12. Some say it harms the Ozone and others say it doesn't. I would ask your local automotive shop or maby one of the experts could chime in here on this topic.

 

[Haynesie]

just for kicks, how would you go about doing it with r12, like where are the shrader valves that i use, and is their some sort of way of telling if i have filled the system up, without a gauge on the hose

 

[Red Regal T]

You install the coolant into the low side nipple, located on the dryer. If your ac isn't cold, or if your compressor is not engaged or is clicking on and off, your probably at least low on Freon. Because R-12 is expensive and hard to come by, it is a good idea to change over to 134A. Takes about three cans from empty. Good idea to istall a small can of oil. The cooler you can get your car to run, the colder the AC will be.

 

[chrisgarrett]

134

Can you just hook up the R134 and pressurize it? Don't you need to vacuum the system out to clear out the old R12 oil and remaining refrigerant? I'm just asking. I know nothing about this. I would love to switch over but I didn't think it was that easy. Chris

 

[Haynesie]

I know that if you put 134, with r12, then they will have a chemical reaction and crystalize, and you will have destroyed all your lines, and anything else with r12 in it, DO NOT MIX THE TWO TYPES OR YOUR IN FOR A LOT OF MONEY LATER ON OR NO AC.

Where is the dryer located, and is their a small glass where i can see if their are still bubble of air, or do i need to have a gaughe, and yes the compressor is turning on and off on and off on and off etc.

 

[Red Regal T]

Re: 134

Originally posted by chrisgarrett
Can you just hook up the R134 and pressurize it? Don't you need to vacuum the system out to clear out the old R12 oil and remaining refrigerant? I'm just asking. I know nothing about this. I would love to switch over but I didn't think it was that easy. Chris

Just bleed off the R-12. There probably isn't that much oil in your system if any. Here's a progression of what I've done over the past four or five summers, maybe longer. Cooling low and with the expense and difficulty of getting R-12, I changed to freese -12, a substitute. When my canister of that product ran out, due to a minescule leak, I just started using 134A. Just put it in. I've since, over the years replaced my compressor with junkyard units from early 90 Camaros, twice, and am on the second now. I replaced the drier and orifice tube each time I replaced the compressor. I never evacuated the system. I'm using the 134A now. Don't forget this is over a 5 year period and summers here are six months long.

 

[Haynesie]

hmmm, well i have plenty of the r12 at my disposal if i plan on using it, and i dont feel like going through that five year routine haha, so i guess ill just have to see what happens, maybe get a quote to see what changin it over costs from a mechanic of mine

 

[VernLee]

I know my system is clear, except my compressor, do I need to pull the compressor off a drain the old oil, ? and do you have to pull compressor to drain it ?
Vern

 

[chrisgarrett]

I think I will play it safe and have the system vacuumed out and then I will add the 134. Once the thing is cleaned out, I can start to service it myself with 134. I'd rather spend the money and not do anything to hurt my baby. JMO

 

[Red Regal T]

Originally posted by VernLee
I know my system is clear, except my compressor, do I need to pull the compressor off a drain the old oil, ? and do you have to pull compressor to drain it ?
Vern

There may or may not be oil in your system. Just like the freon leaks off, so does the oil. If you're going to change over to 134A, replace your dryer with a new one, about $30, and also replace your orifice tube. $2. Don't bother with a variable orifice tube. They're about $25 and really do nothing.

Yes, by all means, those who want to, check with your mechanics so they can tell you horror stories that, in some cases, they actually believe. The main horror story is the BS that's been put out there by AC repair facilities, for the purpose of emptying your pockets. Do what you want. It's not costin me anything. Good luck!

 

[Haynesie]

Red, im not saying your method is wrong or anything, im just saying i dont have the know how to be able to do what your speaking of, it may seem simple to you, but it just can be describe in complete detail over the board, at least not in a mannor that i can understand, that is why i will take it to a mechanic who charges a fair price and has converted all my other familes' cars to 134.

 

[Sleeper-6]

Just to carry this on farther, What are the pressures one would see on a properly charged system. I have access to R-12, We vaced down the system, it held vacume, added a can or sealer, and refilled with R-12. Unfortunately we didn't pay attention to how much freon it was refilled with. Now I'm not sure if I'm slightly under or over charged. My vent temps aren't as cold as I feel they should be. Could I judge from static pressures, or does it have to be running?

 

[norbs]

YOu have to have it running. The temperature entering the evap has to equal the temp leave the evap. If the pipe with the orifice tube is colder than the pipe to the top of the accumlator the system is undercharged, if its opposite its overcharged. SImple test. you need to have two thermomoeters though

 

[Sleeper-6]

Well that makes it easy! Thanks!

 

[Red Regal T]

Generally speaking, your low side pressure should be around 30 psi and the high side around 250.

The point I'm making about charging an AC system, or changing over to 134A, is, that it isn't as mysterious or as expensive as most "technicians" might say it is. If there is no problem with your system, it shouldn't cost much to get it blowing cold. At AC shops, it's nothing for them to quote a $500 estimate, when you could have a charged AC system for under $15. So be wary.

 

[jacksorroche]

Not to play devil's advocate here guys, but here are some legalities on this AC stiff: In order to do any R-12 work on any vehicle, you must be certified. You also have to have the proper vacuum/charge/filter equipment. Venting any Freon to atmosphere is illegal, since it is an Ozone depletory. On that same token, no certification is needed for any work on an R134a system. You can even buy R134a without any certification.

By the way, when I tested AC units on bulldozers, I used to just put a thermometer in the AC vents; the output should be approximately 15 to 20 degrees below outside temp, anything lower than that required a charge.

 

[Turbo6inKY]

Originally posted by chrisgarrett
I think I will play it safe and have the system vacuumed out and then I will add the 134. Once the thing is cleaned out, I can start to service it myself with 134. I'd rather spend the money and not do anything to hurt my baby. JMO

In Louisville, you can call up an A/C place and they'll suck down your R12 system for free. They recover the R12 and sell it.