How do I recharge a/c

[g-mony]

I have a 06 Commander 4.7L & would like to recharge a/c. Which refrigerant do I get? Which line do I connect it to? A pic would be helpful.
Thanx

[Smitty1970]

The refrigerent used is classified by the .gov as a hazardous material and you have to have a license to buy it. An auto repair shop or collision shop also have to heve an evac / recharge machine designed for this. Take it to a shop. Sorry

[jcoulter]

Originally Posted by Smitty1970

The refrigerent used is classified by the .gov as a hazardous material and you have to have a license to buy it. An auto repair shop or collision shop also have to heve an evac / recharge machine designed for this. Take it to a shop. Sorry

You sure? I remember R-12 being that way but I'm pretty sure you can walk into Autozone, Wal Mart, Farm & Fleet, etc. and buy R-134 kits.

[Kansas1230]

You can buy R-134a recharge "kits," but what you don't have in your garage is the aforementioned evacuation vacuum.

Without this you won't be able to:
1. vacuum test the system for leaks (the probable cause of your low freon now)
2. measure how much freon is currently in the system
3. recharge with the correct amount of new freon and oil

As hard as it is for us DIY guys to accept, this is one of the few services that really should be done at a shop. Find a mechanic you like, read a good magazine while he labours over your A/C lines, and enjoy cold air for the rest of the summer (his service probably comes with some warranty too).

[bob123]

I believe this is safe to use since it has a built in pressure gauge.

http://www.id-usa.com/product.asp?CID=27&PID=212

[robby]

Really, you should own a manifold gauge set to determine if you need a touch up (low operating pressure) and you can then bring the pressure up to spec.
By having the gauge set though, you can determine if you lost most of the charge and, if so, then get it leak checked and repaired correctly.
Even though the manufacturer has made these systems with the best seals money can buy, 134a by virtue of its small molecules, seems fairly good at working its way out, especially from the compressor shaft seals.
So, a lb. or less touch up after a few years in service is not the end of the world, but a 2 lb. loss since last fall would require leak testing and repair.
BTW, these systems carry most of their refrigerant oil with the refrigerant.
Best visualization is a two stroke engine using a fuel/oil mix.
If your system has lost a pound or more, there likely is a corresponding loss of refrigerant oil.
If you were to charge with 134a only, the reduced lubricant being carried with the gas, could lead to a oil starved/destroyed compressor.
So, the addition of freon is not to be taken lightly.

Rob

[powerslave1966]

Originally Posted by robby

Really, you should own a manifold gauge set to determine if you need a touch up (low operating pressure) and you can then bring the pressure up to spec.
By having the gauge set though, you can determine if you lost most of the charge and, if so, then get it leak checked and repaired correctly.
Even though the manufacturer has made these systems with the best seals money can buy, 134a by virtue of its small molecules, seems fairly good at working its way out, especially from the compressor shaft seals.
So, a lb. or less touch up after a few years in service is not the end of the world, but a 2 lb. loss since last fall would require leak testing and repair.
BTW, these systems carry most of their refrigerant oil with the refrigerant.
Best visualization is a two stroke engine using a fuel/oil mix.
If your system has lost a pound or more, there likely is a corresponding loss of refrigerant oil.
If you were to charge with 134a only, the reduced lubricant being carried with the gas, could lead to a oil starved/destroyed compressor.
So, the addition of freon is not to be taken lightly.

Rob

I concur.

[Fohn_Jargo]

After going to, and dropping out of, HVAC classes, I can tell you that there are so many variables associated with "topping off".

Heat, humidity, type of refridgerant all matter. When measuring the proper amount for your system, they need to know how much by weight, not psi, belongs in your system.

To get the proper amount in, they first must vacuum your system to a recovery tank and weigh it. They will determin how much to add from there.

If you get it wrong you risk adding to much and blowing up your compressor; ie hydrolock. If you add to little you risk short cycles and frozen condensation and overheating of the compressor.

So, you could try and do it yourself and keep your fingers crossed, take it to a shop where they will do it right and probably warrenty the work, or spend the summer sitting on bags of ice.

[Steve]

I have to partly agree with the forum. As a DIY guy, I am unable to properly evacuate R-134a and measure the system properly when recharging.

However, the repair aspect of the system is not hard for a DIY guy. Hayes has a great Heating and Air Conditioning book that is a great overview of the A/C system, troubleshooting and repair. The manufacture's service manual is a MUST for your make/year. The actual repair of the system is doable in my opinion. My chain auto part store (don't know if I can say the name) has a vacume pump they will loan you to suck it down to vacume. However, you have to find a local shop that will empty the R-134a in the begining and recharge it on their machine when the repair is done. This was not hard to do in my area. This way you know that the right ammount of R-134a (and oil) is in the system to prevent long term damage as others have said.

I've converted a '93 Saturn SC2, complete rebuild of '90 Honda Civic, replaced evaporator coil in '01 XJ. Our XK is solid. I haven't touched it yet. All with the help of the Hayes book and my service manuals. If your a self sufficient type guy responcible for and to yourself, I say go for it. I've saved a bunch of cash, learned some new things, and I enjoy it. (Yes. I know. I'm weird.)