Re-charging the AC

PETER PEARCE · Jul 29, 2010

Has anyone tried to re-charge their Air Conditioning ??

It's was easy in my Durango but it looks a little more complicated in my 2005 Sport Trac.

Thanks,

Pete

JohnnyB · Jul 29, 2010

It should not be much different. The thing is if you have a leak you are going to loose it anyway. A/C systems are sealed systems you are not supposed to loose freon/refrigerant at all. If you did then you have a leak, it could be a small leak that takes weeks or even a few months but a leak none the less. Sometimes a slow leak is the schrader valve where you are putting in the refrigerant.

If you want to take a shot at it you can try a can of R134a with a sealer in it. I have found that most of the time it does not stop the leak. Also they have cans that have a sealer and a leak detector in it. That can be helpful to find the leak.

They also have a small can of sealer that comes with a guarantee if it does not fix your leak you get your money back (keep the can and your receipt, you have to call the 800# on the can and mail in your receipt) it is about $40.

You can refill your system a couple times but eventually you will need to get it serviced. You could end up with too much oil in they system which will eventually hurt the compressor. That 1 lb can of freon is part gas and part liquid, the liquid being the oil. When you turn the can over you are adding oil to the system, holding the can upright and shaking is adding the freon.

Look at the sticker under the hood and see how much freon your system holds. Buy the amount of freon accordingly. Also helps to get one of those thermometers you stick in the air vent to see how cold the air was before you started and after.

Good Luck.

scott degroot · Jul 29, 2010

JohnnyB,7/29/2010 04:13 MT

Look at the sticker under the hood and see how much freon your system holds. Buy the amount of freon accordingly. Good Luck.

The problem with this is that one assumes that the system is completely out of refrigerant. 99% of the time the system is just low enough that there isn't enough pressure to turn the system on or the system short cycles. If you go and add the amount of refrigerant the sticker says then you end up with a system that is overcharged and doesn't cool properly and then most people will keep adding refrigerant because they think that more is better. Guess what I am saying...and always have on this and other forums...if you don't know how to do ac or don't have the proper equipment then leave it to the professionals

Dreman · Jul 29, 2010

If the can says "Freon" and does not say oil, there isn't any oil in it. A can of freon is almost all liquid when you get it because there is too much freon under too much pressure in the can for it to stay a gas and have it all fit in the can. Freon is supposed to go through the phase change from liquid to gas as you put it into the AC system. It goes through the same phase change and back again when it is making the air cold in your Sport Trac. That's what it does to make it cooler inside. Be careful with turning the can upside down when you are charging the AC system, because you are putting in liquid freon. It does expand and turn into gas pretty quickly, but it's better to get the can to empty into the system as a gas. Lightly shaking the can while it empties causes more liquid freon to turn to gas and exit the can. An old trick is to put the can in a pan of warm water when it starts to get cold to add heat to the can to make the freon into a gas in the can and then go into your AC system.

Todd Z · Jul 29, 2010

As a temp fix the cans are great...... as a permanent safe fix Let the Pros do it..

Todd Z

Richard L · Jul 29, 2010

l1tech is correct.

The days of just adding a can of refrigerant are long gone.

If your system is low on coolant, it simply means you have a leak and that needs to be fixed.

You cannot recharge a low AC system if you do not know how much has leaked out or how much is left in the system. Also, to fix the leak you will need to completely discharge the system.

Another factor often overlooked is that when the refrigerant leaked out compressor oil leaked out too. Each system needs a specific amount of oil an will not operate or perform properly if there is too much or too little.

In addition, when the refrigerant leaks out, the system will often suck in some air which contains moisture which will freeze inside the AC system, usually at the Orfice tube or H-valve where the liquid refrigerant expands into a cooling gas.

So to fix the leak you need to open the system and to refill the system you must start with NO refrigerant and no oil in the system. It is also usually required that you change the Accumulator/Dryer or replace the Desicant inside the dryer to absorb any moisture in the system and prevent internal freezing.

Finally, to properly recharge an AC system, you need to run a vaccum pump on the system for to evacuate all the air out of the system before introducing the precise amount of refrigerant and compressor oil.

Adding a can of refrigerant is not even a good temporary fix, and often does more harm than good.

...Rich