AC recharge

[Jerryl]

Another diamond in the rough :biggrin:

 

[xrunner123]

Here's a good write-up by Jim Testa.
http://gnttype.org/techarea/airconditioning/ac101/ac101.html

 

[FlyinGN]

no such thing as 'just needing a recharge'. Its a closed system and the charge should never deplete. You also have a leak that must be found if you want it to work for good.

just needs a recharge, how do i do it?

 

[Fuelie600]

Not a GN, but here is my take. When my Villager lost it's cool, I installed an adapter to accept the 134a charge hose, ( bought a kit from Autozone )
and filled her up using to the included gauge. It's been ice cold for 2 yrs, with occasional top offs. Personaly, I don't care if the villager A/C system craps out, but it hasn't yet.

 

[2badgn]

There may or may not be oil in your system. Just like the freon leaks off, so does the oil. If you're going to change over to 134A, replace your dryer with a new one, about $30, and also replace your orifice tube. $2. Don't bother with a variable orifice tube. They're about $25 and really do nothing.

Yes, by all means, those who want to, check with your mechanics so they can tell you horror stories that, in some cases, they actually believe. The main horror story is the BS that's been put out there by AC repair facilities, for the purpose of emptying your pockets. Do what you want. It's not costin me anything. Good luck!

Where can i buy dryer, orifice tube and retrofit kit with all the o-rings to convert from R12 to 134a?

thanks
Frank

 

[BlackBandit]

no such thing as 'just needing a recharge'. Its a closed system and the charge should never deplete. You also have a leak that must be found if you want it to work for good.

I thought that when you converted from R-12 to 134A it wasn't uncommon for the system to bleed some some coolant over time (albeit not much) do to the decrease in the size of the molecular chains that make up 134A and the required increase in head pressure. I was under the impression that the only way to overcome this was to replace the seals in the system with a type designed for 134A. Also I've heard retrofitting can cause premature compressor failure when using compressors designed for R-12 again due to the higher pressures.

Don't get me wrong, I'm not sayin' that if you retrofit your system is going to fail, (mine is retrofitted) I'm just sayin' it might require a minimal amount of extra maintenance.

Also, I had an A/C guy tell me that the "secret" to getting an A/C system to blow really cold is to make sure there is NO moisture in the system. In other words have it vacuumed.

 

[Heath]

I went to 134a and I did not like it. Did not cool as good.So I went back to r-12.

 

[BlackBandit]

I went to 134a and I did not like it. Did not cool as good.So I went back to r-12.

Like I said, you have to vacuum the system. Also, you can adjust the pressure switch. Other than that, and making sure everything is perfect, you kinda just have to live with what you got. You should be able to at least get close, but don't forget, R12 is just about the perfect refrigerant. Hard to compete with that.

 

[Fuelie600]

I went to 134a and I did not like it. Did not cool as good.So I went back to r-12.

If I could find R-12, I'd use it too. I'm jealous :biggrin:

 

[ty1435_4.3]

I did my own conversion. Car was sitting for 2 yrs and was dry. So I vaccumed the system changed dryer and orfice tube and recharged with R134. Now you have to look for the oil that says " O-ring conditioner" that will keep the o-ring soft so they will not harded up and crack. Also for added protection I added a can of stop leak. I have a themometer in the vents and its reads from 37-45 deg. and that the vent next to the drivers door. I also have no tints so I take a few more mins. to cool on a hot FLA. day but I am happy.

If there is any R12 left go to an A/C shop and let them suck it out. Just to be a good person. The Drier is easy to change and so I the orfice tube. Just ALWAYS use 2 wrenches so you dont twist anything. And when you are done go back to the A/C shop and have them vacuum the system out. Then you do the rest. Im sure if you have any question the guys here can help.

 

[acoen]

I'm going to replace my compressor, I can get R-12 but I'm thinking of using Duracool any thoughts? Not trying to hijack the thread, I just thought it may be another approach. Unless you guys know something I don't. Duracool is an R-12 replacement, I believe it is butane. May be a better way to go instead of going to 134R

 

[ty1435_4.3]

But are they still going to be makeing it in 2,3,5,10 yrs from now? At least here in Miami the inspectors came in and made us take every can of replacement r12 off our shelves. I hear of people saying that it doesnt cool the same as r12. But from my experience I cant tell any difference when the swap is done right.

 

[aminga]

But are they still going to be makeing it in 2,3,5,10 yrs from now? At least here in Miami the inspectors came in and made us take every can of replacement r12 off our shelves. I hear of people saying that it doesnt cool the same as r12. But from my experience I cant tell any difference when the swap is done right.

They aren't making it now. An EPA regulation several years ago banned new production and imports of R-12. In the late 90's the most recovered contraband item coming across the TX border crossings wasn't Drugs it was R-12. The only R-12 available now is from recycled stocks obtained from recovery of existing R-12. Unfortunatly that's dindling from folks topping off R-12 systems with replacemnts like Freeze-12, blends aren't recoverable.

 

[aminga]

So here's my take on R-134 and cooling from a little experiment I just completed. Until my compressor went belly up this may, I resisted the urge to switch because R-134a didn't cool as well and that's partially true. On a 100 degree day with a properly charged system An R-12 system should have an evaporator temp in the low 30's while an R-134a should have one in the mid 40's. I'm talking about the temp of evaporator not the air exiting the register here.

The cost of R-12 to charge a depleted system now runs around $150 not including labor. It was cheaper to switch than fight considering I need a compressor anyway. I'ts almost cheaper to convert if you don't need a compressor or it will be soon.

When I was replacing the system I did a little experiment. For the 100 degree day I was working in an R-12 system should have a head pressure of 250psi and a lowside of 28. So I charged the system to that level. It only took about 1.5 lbs of refrigerant to get to those pressures the system will hold 3.25 lbs. And I took a little ride down the road so I would have the full benefit of airflow across the condensor (face it the regal system was always a little slow to respond even new). Register temps were in the mid 60's with the system operating at MAX A/C and were very slow to respond.

Then I topped the system off with 3 lbs of refrigerant. The Head pressure rose to 325 PSI and the low side came up to 50, normal by everything I've read for an R-134a system and similar to my 99 chevy truck with a factor R-134a system. Now on the road the temps will go down to 43 degrees and the system responds much like the Old R-12 system did.

It may not cool as well as R-12 but 43 degrees is plenty cold (again about the same as my truck and the wife's 03 GP) The system will maitain the cabin at a comfortable temp with the system backed off considerably. But it does so at a much higher pressure level one that the 20 year old Harrison compressor won't live at ( for long) and IMHO that is why we don't see R-134a converted systems cool as well as R-12 because they simply aren't charged enough.