R-134 A/C recharge question

[JKurley]

When i bot my truck, it had R-12, and it was ICE COLD. Its been converted to 134, and while its not as cold as the R12, its still very comfortable, at least it was last summer.



I want to throw a pound of 134 in it, and my question is-do you connect the can to the fitting closest to the radiator, or the one closest to the dash? Thanks for all help!

 

[Dfeland]

Why do you want to "throw" in a pound which is 16oz which is half of the total capacity for 134a? If it blows cold then I would not touch it becuase it sounds like you are not equiped to check the high side pressures and if you over charge it R-134a runs higher head than 12 you can cause compressor damage. You should recieve approximately a 25 degree drop from cab temp and discharge air. If you have that you are probably pretty close on charge. Also if for some reason you have a sight glass it will not clear with 134a so don't use that as an idicator of charge.

 

[MRickard]

Depends if you are to fill it as a gas or liquid (low/high side) but Dfeland is correct, you do not want to overfill it. If you think it is low, I would test it/replace it with the correct amount, and check the pressures unless you have a pile of good compressors. R-134a does have a tendancy to leave the system or R12's, so it is possible that it is low. The temp of the air could be lower due to other things, most notably the efficiency of the condensor. I would not just throw in a pound just because it is not cooling as good, unless, of course, you have a lot of free spare parts

 

[dusthomps]

I actually over filled mine the first time I recharged with 134a. The compressor has a high pressure relief valve when too much is added to the system. Once enough has been bled off, the valve will re-seat itself. I thought for sure I had ruined something in the compressor the first time, until I sat and read through the FSM. Two years later, it still blows cold air.





Dustin

 

[CKnoop]

I am going to do that to my truck this weekend it is totally emty.
I have to flush out everything that stuff aint cheep $22 a quart havent bought it yet just priced it. what are the correct guage readings if everything is working right? been a while since I messed with AC on the sight glass thing not being clear like r12 what abought a system that originally had 134 in it? I charged my brothers Dodge Van 98 till sight glass cleared up compressor would cycle before did I mess up? will hook up guages this weekend may have to bleed some off he said it is working fine nice and cold thanks

 

[JKurley]

OK, guys, I'll just put in a little can of 134 then, but back to my original question- is the fill fitting closest to the radiator or the cab? Thanks for any help.

 

[dusthomps]

I've always used the fitting closest to the cab (low pressure side) when I've added 134a to my trucks.





Dustin

 

[Greenleaf]

Dud! Low pressure side.

Have the pump running and she'll pull refrigerant from the can. Gas only please



You will look for 24 to 44 (?) psi here w/pump engaged.



The low pressure port is next to the thermostatic expansion valve at firewall. (Bet some of u guys didn't know a bus mehknic knew that!)



-S

 

[Forrest Nearing]

go to www.duracoolky.com



read...



order some duracool...



enjoy your cold AC



I've been using it for years in R-12 AND 134 systems. it's BETTER than r-12.



tell Gerald that Forrest Nearing sent you.



Forrest

 

[csnider]

Interesting stuff ... The only scary thing is the cumbustability!. .

Do you ever have any probs with icing up?. . Also does this product mix with R12 or do you have to evacuate first... ... .

Thanks for the info... ...

 

[csnider]

Never mind,

I found the instructions on the web page... Thanks again. .

Interesting stuff... .

 

[Forrest Nearing]

134 is combustable too!!!! and at a LOWER temperature!!!



autoignition temperature of Duracool is ~ 1625*F



autoignition temperature of r134 is ~ 1418* F !!!! (pulled from DuPont's website)







I don't tell many local folks about the stuff because I make good money installing it in their cars



but I'm tellin' ya, it's the greatest thing since sliced bread.



Forrest