A/C Experts - R-134 Recovery

[moondoggie]

Good Day!

[b]Is there any reason I can

[GMC Hauler]

You can't without another compressor unit. It does a phase change coming out of the can, which you have to do in reverse to store it in the small can.

I just bought 4 cans at walmart. They were $8 each.

[kevin77]

do you think an old compressor out a freezer or fridge would work? I once took an old compressor out of a freezer and converted it to a vaccum pump. You would probly want to put a gauge on the pressure side just to be on the safe side.

Kevin

[kevin77]

I did my AC repair last year on my 94 suburban, replacing compressor, orifice tube and rear expansion valve (parks from autozone and dealer)

Still leaked a little and didn't work that great.

After investigating, I found that the compressor was leaking and when I pulled the belt off, the clutch was loose. Soo, I ordered a new compressor from Arizona Air, a new VOV orifice tube and an accumulator. Evacuated the system and recharged and now it works good.

If you had to clean your orifice tube out then your expansion valve in back is probably blocked or near blocked. I wonder if you have a blockage in the condensor. That could explain high pressure but lack of flow/cooling?

Did the AC shop flush the system?

Check out http://www.ackits.com/index.cfm?fuseaction=flush on the flushing procedure to get everything sparkling clean inside.

Kevin

[kevin77]

That message didn't go where I intended it to. And to think I have a computer science degree. ;-/

Kevin

[DmaxMaverick]

moondoggie

To answer your question, yes. As far as safety goes, there should be too little propane residue left in an empty bottle to effect your A/C system. In some areas of the world, propane is used as THE refrigerant, and is comparible with R12. If that sounds stupid, it's probably the reason it isn't legal in the US. Also, pressurizing the bottle with dry air, or nitrogen to about 200 PSI, inverting the bottle, and releasing the pressure should remove any remaining propane.

Unless you have a refrigerant evacuation unit, or a suitable vacuum pump, you won't be able to get enough refrigerant into the bottle. It needs to be vacuumed out, then compressed into the bottle to get it back to a liquid state. Storing it in a gas state won't gain any ground for you.

Years ago, I've used empty R12 bottles for portable air tanks. They had no check valve, and you could buy a "kit" at any auto parts store to help you do it if you didn't have the parts. I don't know about the 134 bottles. There may be a check valve, as you suspect. The R12 bottles usually only lasted about a year, as the blow-out plug would develop rust and leak.

[moondoggie]

Good Day!

GMC Hauler said, [i]

[DmaxMaverick]

The ice water is a good idea, but will fall short. Even heavily salted water can only get down to about -10

[moondoggie]

Good Day!

Wow, am I glad I asked. It looks like, as a practical matter, this won't work. :confused: Oh, well... The outfit I mentioned will still eval & evac the system for $35.00 - maybe I can talk them into simply evac'ing it for a better price.

If I don't find a better price for R-134, it really doesn't matter: $75 - $90 per fooling-around-session is too much. Guess I'll survive with out the A/C.

Thanks for not calling me an idiot. The facts did a really good job of that anyway. :rolleyes: At least this information will be available to search, should someone else be so foolish. :D

Many thanks & Blessings!

[DmaxMaverick]

On that note, I know shops that will evac. a system for free, unless you ask what they are doing with the refrigerant they reclaim. Most count on your not asking, and they will sell the stuff to the next customer. If they reclaim 4#'s from your system, and charge you $35, what is it really costing you? The recovery system will tell them exactly how much they recover. The oil is separated, so it is not part of the net weight.

A good shop will do a recovery/evac. and give you a credit on what they actually recover. When they do the recharge, you get your refrigerant back, and only pay for any more you need. Of course, if you have it recharged elsewhere, you loose the credit. At least it is a fair practice.

[GMC Hauler]

Don't sweat it. It's thinking out of the box like what you were atempting that makes this page great. :D

[Scooby]

MOONIE- I do AC work, and through the years have used many methods to draw refrigerant out of systems. WIthout a recovery machine, it is hit and miss. Do you have a vacuum pump?? I would first pull a vacuum on your propane tank, (have a shop pull vacuum for you), put the tank in the ice bucket, and let it sit an hour or so. With your compressor running, open the high side valve on your manifold set. I believe the fitting is in the liquid line, so you should be drawing liquid out at that point. Once it has pumped out all it will, turn off the truck, and let it sit at least 4 hours. The heat in the engine compartment will increase system pressure, and the cold around the tank will lower the liquid pressure. Freon will liquify and seek the coldest point in a system, which will be your tank in the ice. This method will get the most out you can without a recovery machine.
I have made recovery machines from old water fountain compressor- condensor units. You need compressor, condensor, & fan to recover refrigerant. Just pumping the gas wont work cause it will not condense without being cooled down.(condensor) .
Thats my thoughts.

[moondoggie]

Good Day!

DmaxMaverick: Thanks for your very professional assistance. You (& others here on the Page) are like Dr. Lee: I couldn

[damork]

Scooby is right - and the trick with an old refrigerator compressor is on target. I've done it before and it works great.

[GMC Hauler]

have you found any refrigerant cheaper than $15 a can?

[Peter J. Bierman]

Moondoggie,

Actualy your idea is not so weird.
When I got training for A/C systems we learned to do as much evacuating and charging with the system compressor as we could.

First, get your bottle as clean as possible and evacuated.

Second, let the a/c run for like 10 minutes and then shut it down, open the hi pressure side and let the refrigerant flow in to the bottle till you no longer hear it flowing.Shut the valve on the service port.

Let the system warm for a wile so the refrigeant will evaporate from the oil.

Repeat this a few times till the low pressure switch cut out the system.

If you now cool the bottle and heat the A/c system by running the engine and heater so the a/c can accumulate some heat.

If the bottle is cold, the pressure inside will drop so the pressure inside the A/C sytem will be higher, if you now oper the port, more refrigerant will flow to the botlle.

This way you can recover like 80 % of the refrigerant. smile.gif

For charging, you warm the bottle and put it up side down and connect it to the low pressure port.
Evacuating the air from the A/C system will help get pressure differance.

The refrigrant will now flow in to the system.
Once the pressure switch kicks in you can start the truck and let the compressor suck in the refrigerant.

This way you can put 90% off the bottle contence back in. smile.gif

But BEWARE, :eek: you have not all refrigerant out, so be carefull when cracking a line open, the remaining refrigerant can still cause frost burns.
So carefully let it blow off before you totaly unscrew the fitting.

Good luck, Peter

[moondoggie]

Good Day!

damork: It

[Peter J. Bierman]

Leaving the container connected overnight won't do you any good.
The whole process is based on pressure differances, so it will not take much time to level them out and then the flow stops.
The cooling of the container is used to lower the pressure in there and get a little more out of the system.

The vacuum leak test is not realy a poor mans thing, we are ( in the Netherlands ) demanded by law to draw a vacuum off 2025 microns or more ( less ) and hold that for 30 minutes. if you can hold that the system is tight.

This method proved to be more reliable then the fancy electronic "sniffer" especially when you are outside and there is more then zero wind.

Fluodye is great to confirm the leaktest after a few day's, no greenish/yellowish stains and you are OK.

Peter

[BobND]

Peter,

That's not entirely correct. Given some time, the condensed R-134 will seek the lowest level. If the "recovery bottle" is sitting on the floor next to the vehicle, the R-134 will MOSTLY wind up down there, given time.

[Peter J. Bierman]

Right, but it would be hard to keep te container cold overnight, if the container warms up again the flow could go back into the system couse the pressure still levels out.

To be short, you can recover most of the refrigerant without a recovery unit.

Peter

[moondoggie]

Good Day!

Cool! Now if I can just get time to get at this... :( When I said above that I had lots of time, what I meant was that leaving something connected overnight was no problem. Unfortunately, actually getting time to fool with this thing (& lots of other stuff I'd like to do) is close to impossible.

Blessings!

[tom.mcinerney]

Nice thread. A slightly O/T offering to DMax:
<http://www.usna.edu/Oceanography/courses/SO426_maksym/text/chapter3_iceformation.htm>

This is irrelevant in MN.

[moondoggie]

Good Day!

The formation of ice is "irrelevant in MN"????? You've obviously never been to MN!!!!! ;) We're not making ice now, but wait a couple months... :eek:

Blessings!

[tom.mcinerney]

I had to suck you into that neat link, Moon. I've noticed that your curiosity survived HS intact.

There are vast differences between fresh water and
brine freezing. The crystallization of brine is used in technical discussions when introducing the freezing of iron and carbon (ie., steel) as there are marked similarities. I think both salt and carbon are soluble in liquid phase, but insoluble in solid phase. I did some reading while researching welding....and found i knew near nothing about both brine ice and steel!

[moondoggie]

Good Day!

Usually I hear a sound like a jet going overhead when I read such, but that's so far over my head I didn't even hear the jet go over. :eek:

Blessings!