Is there a GRM way to evacuate and recharge an A/C system?

I was getting an alignment done when I asked them to take a quick look why my A/C was blowing cool, but not cold. They said the pressures were off and I needed an evacuate and recharge. With my mustang, I rented the vacuum pump and did all that fun stuff but the system was already empty. Now I have a partially full system and I'm not sure what to do. Purging into the atmosphere isn't going to happen...any other way?

I'm thinking you'll have to have a shot evac the system. Once it's evacuated you'll still have to pull and hold a vacuum at home to boil the water out before you add the refer. I'd ask how much it is to just evac it, and to complete the job. Might not be that much more to just have them do it.

If there's still some refrigerant in there, is there any reason to pull a vacuum? Couldn't he just add refrigerant?

Pulling the refrigerant out is a job for someone with the equipment to do it. A shop will do it for you at a reasonable cost. Recharging from empty then you pull a vacuum and hold it for a while to make sure the water is all gone from the system. Putting the refrigerant back in then is just a simple matter of refilling it. In your situation I would just add refrigerant. Do you have any a/c service tools? I bought a manifold set and a big r134a tank and a vacuum pump. It's been worth having. Unfortunately I'm a long way from you - a little too far to help. ;-)

dculberson wrote: If there's still some refrigerant in there, is there any reason to pull a vacuum? Couldn't he just add refrigerant? Pulling the refrigerant out is a job for someone with the equipment to do it. A shop will do it for you at a reasonable cost. Recharging from empty then you pull a vacuum and hold it for a while to make sure the water is all gone from the system. Putting the refrigerant back in then is just a simple matter of refilling it. In your situation I would just add refrigerant. Do you have any a/c service tools? I bought a manifold set and a big r134a tank and a vacuum pump. It's been worth having. Unfortunately I'm a long way from you - a little too far to help. ;-)

Thanks for the help. I don't have the A/C service tools, but I wouldn't be opposed to buying some. Most of them can be rented (I rented the vac pump and manifold for my Mustang). He wanted to pull vacuum/evacuate because he thought there was air in the lines. Should I add refrigerant by getting the can from advanced auto or do the whole shebang with manifold?

I'll keep it short and sweet to keep you guys interested...but here is my hypothesis:

While sitting at a stop light a year or so ago, my car made a hissing noise and then went up in smoke. I'm not talking a little smoke...im talking like can't see 2 feet out of the car huge cloud of smoke. There was a big hissing noise and then it stopped...the smoke went away and I wasn't on fire. (see : http://forums.tdiclub.com/showthread.php?t=331852). Car seemed to be fine so I went on my way. Shortly afterwards I noticed my a/c was blowing cool but not cold. Then it stopped working completely. Some trouble shooting later I determined my clutch was dead. I replaced that (without opening up the system) and now it's where I am at now. It blows cool, but not cold.

My theory is somehow the pressure over pressurized with the crazy clutch. That vented refrigerant and caused the smoke. Now I am low on freon and the system doesnt blow cold anymore.

Maybe?

Sounds possible.

Yeah the most GRM way to do it is to DIY everything except the vacuum evacuation yourself, and find a cheap shop (ideally a mobile one) to do the evacuating for you.

I once had a shop change an AC compressor for me (including everything, removal, installation and evac/recharge) for under $150, labor's cheaper around here, but still...

Do you know whether you have any pressure at all? If you press on the schrader valves pins with a screwdriver, is there any hissing from gas escaping?

From what you described, I would be expecting that there's a rather large hole/leak in the system from a seal blowing and evacuating all of the refrigerant. Though I'd have expected that the shop that looked at it should have been able to tell that, though perhaps not if they just did a quick pressure check...

Ashyukun wrote: Do you know whether you have any pressure at all? If you press on the schrader valves pins with a screwdriver, is there any hissing from gas escaping?

Hit the LOW PRESSURE valve (black one). And as short as possible, that stuff punches holes right through the ozone layer.

In reply to GameboyRMH:

Static pressure is the same on the high and low side. And there's no definitive proof that ANY refrigerant punches holes in the ozone layer, just theories.

Enyar - If you want help with your A/C, PM me. I've been designing and testing mobile A/C systems for 20 years. I'd be glad to help you.

The shop said I have some pressure, just they were a little low.

Bravenrace, I was hoping you would post here. A previous search seemed like you knew your stuff. PM'd!

In reply to Enyar:

I don't like disagreeing with the experts.