Refigerant vs. Oil ??

[ah1988ford]

I have opend up the a/c system on my van and i will need to recharge it soon, I saw online there is a/c refrigerant (134a) and a/c oil,
what do i need to do to recharge my system? Is the refrigerant and oil the same thing ? Do i need to put some oil and refrigerant in the system ?
I know they sell the cans of refrigerant with the guage and hose on the top at autozone to top off your a/c, can i recharge the whole system using this ?
I need to know what I have to do to recharge the whole system .

 

[icanfixall]

Long before anyone here can answer your questions you have to tell us what refrigerant you have in the system. Its R12 or R134... Thats hopefully the only stuff you might have in there. Anything else will be stuff thats not a good idea.. Like propane and some mixed crap made from a varity of differant things like methane gas like cow farts... That was a swap meet product for a long time. The R12 and R134 use a differant oil so do not mix those up. You will need to vacuum out all the air in the system too once there is any in the system. You can't just add freon to the air in the system. There is also a differant amout of freon used when you install R12 or R134...

 

[dgr]

If you don't have a proper vacuum pump, it would probably be best to have a shop do this. Oil doesn't evaporate so you only have to replace what you dripped out when you opened it.

 

[bab029]

There is a shade tree method of pulling a vacuum that you can use as long as you have a set of gauges and the truck runs. I'd have to sit and remember how I did it. I remember it involved shorting the pressure switch on the drier and waited for the high side to pressure up then cracking the valve on the manifold to the low side while the can attachment is open, or something like that. I remember I could see the water vapor coming out of the hose when you opened it.

I had a leak a few years back and put all new o-rings on. Used some method to pull a vacuum, refilled with 134 and no problems since. (Yes, I have a 134 converted system.)

 

[Leeland]

Check the fill fittings, if they look like regular old schrader valves your system has not been upgraded or atleast not by any one who knows what they're doing. R-134 fittings are quick disconnect fittings and have two different sizes for the high and low side so you cant get the lines backwards when servicing. If your talking about the truck in your sig it should be R-12. It's getting very expensive to find that stuff now days and you will not see it on the shelf at the parts store. IIRC the late 80's most manufactures starting using better lines in anticipation of r-134a, or atleast that's what they taught in auto tech. The deal is the old r-12 lines are porous vs lines for r-134. 134 has smaller molecules than r-12 and if you run it in the old lines it will seep out through the lines. To fill your truck correctly you will probably need to change lines, pump, accumulator, and flush every thing else out because r-12 used a mineral oil and r-134 uses PAG oil and they should not get mixed. It's a pain and it can get expensive. Another difference between the two systems is r-12 uses a expansion valve and r-134 uses a oriffice tube to cause the pressure drop to make things cold. Sorry this response is a little rushed, wife is waiting on me.....

 

[firehawk]

If you are going to keep the truck for a long time, buy a vacuum pump and manifold gauge set and convert to 134a. Do a little research. The job is not hard.

 

[RLDSL]

You do not need to change lines, they thought that would be the case , but soon found that any lines that had been run with r12 with mineral oil, the oil had saturated the lines and would prevent seepage. However if installing any new lines, they must be barrier type hose because they would not get a chance to be mineral oil saturated. Use the search, there's a zillion threads on here on conversions You will need 41.6 oz r134a and 10 oz PAG46 oil after flushing the system thoroughly. If for some reason, you are not going to flush the system as it sounds like you may not have gone into the system very far, use ester oil , but if compressor was replaced, STOP, you have a LOT more work to do if you want it to last more than a year or so

 

[ah1988ford]

Its for a 2000 van with r134a, its my fathers van he decided he wants me to put a new evap and orfice tube in and have a shop charge it.
Thanks for the info, you guys have answerd all my questions, like always

 

[RLDSL]

Its for a 2000 van with r134a, its my fathers van he decided he wants me to put a new evap and orfice tube in and have a shop charge it.
Thanks for the info, you guys have answerd all my questions, like always

If it's a 2000 van then the charge amounts are 44oz r134a 9 oz pag46 with just front air and with front and rear air 64 oz r134a and 13oz pag 46 with system completely flushed, it it was just evacuated and not flushed , just fill with refrigerant and add about 4 oz oil to account for loss with the accumulator change ( add teh oil to the accumulator before charging )

 

[ah1988ford]

Thanks sounds like you know you're stuff, I will save that info for sure !
I Only pulled the evap. do I need to replace the accumulator too? I remember when I had my truck a/c seviced they said whenever they open it up they sould replace the dryer, is this the same with the accumulator ? I am replacing the evap. and orfice tube, I am getting the high performance orfice tube that is for climates hotter than
105F ,do these really work, because in Fl. during the summer it is working at its max.

 

[RLDSL]

Thanks sounds like you know you're stuff, I will save that info for sure !
I Only pulled the evap. do I need to replace the accumulator too? I remember when I had my truck a/c seviced they said whenever they open it up they sould replace the dryer, is this the same with the accumulator ? I am replacing the evap. and orfice tube, I am getting the high performance orfice tube that is for climates hotter than
105F ,do these really work, because in Fl. during the summer it is working at its max.

I would assume that you are getting a variable orifice valve, and yes, I install them exclusively in everything I work on here in Arkansas, but when using them you kind of have to use the charge amounts and pressure charts as a basic guide and go by the duct temps because those things will make your pressures go wacky, low pressures will read way high and high pressures will read low in heat, but you can get amazing duct temps once you tune them in. A good ac shop in your area should know how to charge to them.
Always replace teh accumulator when opening teh system( it is the modern equivilant of a drier , just a terminology change, so no you didnt just get stupid ) it has a dessicant in it same as a drier and in a humid climate once opened, will be no good, keep the replacement unit sealed until ready to install and seal the system so you dont ruin it

 

[Sw1tchfoot]

Yes, Drier/Accumulator is the same thing.

Yes those orifice tubes work good, as long as you have a clean system.. but if the system is dirty any tube will clog. I used one, the pressures were off. I charged by weight but couldn't get it to take the full capacity, but cooled just as well with less regrigerant. I'll top it off with my new canister when I get to it.