AC Recharge: Does it need to be drained first?

[luciusad2004]

Hey guys. I was just curious.

I was thinking about picking up one of the AC Recharge kits but wasn't sure how they worked. I googled it and it said that found a few walk-throughs that mentioned having it drained by a professional AC shop first.

I was just wondering if it's necessary to drain the AC before charging it with the do-it-yourself kits or not. Seems counter productive to pay someone to drain the AC system and then fill it up myself.

 

[F23A1AT]

Do you know how an Air Con works?

 

[RedRyder]

I've recharged the A/C in a couple cars, never thought of draining them. If that's even possible. lol

 

[luciusad2004]

I've recharged the A/C in a couple cars, never thought of draining them. If that's even possible. lol

Maybe i read a bad walk through but it said their were two service ports. One to depressurize the system and one to fill it up.

Good to hear though, I may go ahead and try to recharge it on my own.

 

[F23A1AT]

What exactly is wrong with your AC? Why do you want to recharge it, I presume it isn't cold.

The AC system in you car is a rather complex and dangerous system to mess around with. "Draining" the system involves specialized equipment that DIY'ers generally cannot get a hold of. Pressures inside the high side can be up to 200 psi which is why you really don't want to mess with it. Also, at the risk of sounding like a tree hugger the refrigerant is very damaging to the environment and you if you get it in your lungs.

I strongly advocate preforming automotive repairs if people have the competence, tools and experience. However there are things that even in my very advanced skill I still don't try to do, this is number one.

 

[F23A1AT]

Watch this video and watch his other videos to get a good idea about how to do these things. Click the show more button.

 

[001Stunna]

The recharge kits sold in stores are pretty easy to use.
I'd say pick up a kit that includes a sealer, a can of a/c gas and the gauge needed for it. They run around $50 in here locally.

As for the procedure...
-Turn the car on and set A/C dial to full cold, press A/C button, turn fan on full, leave windows or doors open.
-Open hood and locate the blue covered valve(low side)
-Connect the gauge to it and make sure the connector goes properly in place(it'll sort of click when it goes on)
-If system shows less then 35-40...Connect the sealer to the other side of the gauge and once fully tightened puncture the can and release back the valve to let the sealer flow through. I believe most cans ask to be held upside down.
-As the sealer is entering the system watch the gauge and make sure it doesn't go higher then 35-40psi. If it does STOP charging.
-Run the system for 20-30mins after adding the sealer to allow it to work.

PS. Doing the above will mean that any A/C shop you visit afterwards WILL hate you if they mix the stuff you put in with their freon recover tank. Let any shop that services your A/C afterwards know that you do not have the actual r134a gas in the system.

 

[Sunoveabesh]

Before I did mine it didn't even register as having 5 psi lol
Wal-Mart DIY recharge filled it up to a little under 30 psi and it's worked great ever since
Total cost I think was around $35

 

[FunnyVictor86]

Just add some refrigerant. Otherwise (in short) you would have to recover the current refrigerant, replace the filter dryer, and vacuum the system followed by recharging it the proper amount of refrigerant. I don't know if you have the tools or know how for that.

 

[Elite1JDM]

Ya just make sure all the caps are tight after you charge it. And you wont have to recover or vacuum the system unless you replace the lines or compressor or dryer, because moisture may get in! If you have to put freon in, its because you have a leak so you might want to look for any signs of leaks in the system. Make shure you charge it on a hot day so it will be accurate! good luck