A/C r34 or upgrade? 1992 IDI 7.3L

[92LongBed]

Hi all, so I have the old frion system in my truck and I have no idea if it has leaks etc. The previous seller told me it just needed to be refilled and my A/C system still blows ambient air when I run it. r34 air systems are deemed "illegal" does anyone still actively run that type of A/C and if so how do you maintain or refill the compressor/whatever you'd call it to get that cool breeze blowing again?

 

[Knight_3000]

First off... neither r12 nor R134a are illegal r12 is much harder to come by and as a result is crazy expensive. R12 is also harmful to the ozone which is not good. R134a can be bought at any auto parts store.

There is a new refrigerant called R1234 that is used in some later 2018-20ush vehicles but don't apply here and I think it's being phased out already.

 

[BBB]

Retro fit it to 134a. Add a electric pusher on the condenser.

 

[92LongBed]

Retro fit it to 134a. Add a electric pusher on the condenser.

thanks ill look into this, r12*** sorry bout r34 confusion lol

 

[92LongBed]

First off... neither r12 nor R134a are illegal r12 is much harder to come by and as a result is crazy expensive. R12 is also harmful to the ozone which is not good. R134a can be bought at any auto parts store.

There is a new refrigerant called R1234 that is used in some later 2018-20ush vehicles but don't apply here and I think it's being phased out already.

thank you, i've looked on ebay for r12 refill cannisters and they're definitely up there but not outta my price range when comparing refitting my AC to r134. i'll see what i can do

 

[chris142]

Where are you at? I specialize in auto ac. First thing is to check the orifice tube for contamination then pressure test the system and look for leaks.

 

[Nero]

When you retrofit, it would be best to replace all your system o rings as well, along with changing the fixed expansion valve to the red one and new dryer. Charge will vary, I put 2.7lbs into my crew cab, but I also swapped my condenser with one from a 1995 pickup with the updated style condenser. Worked pretty good.

The other problem with it is the molecules of 134a is smaller than r12, so your rubber hoses may allow it to seep out over time. Replacing both of them will help with longevity.

 

[quickster]

I have to do my 91 ac. Is there a seal kit that's sold? When it comes to ac, I haven't a clue. And I take it you need a special setup to pressure test?

 

[Nero]

I just bought a universal o ring kit from napa, New ones are green, the ones you'll take out will probably be black or brown in color.
As for leak testing, yes you either vacuum it to 29inhg of vacuum, or pressurize it to 350 Psi with nitrogen and then hit it with soapy water.

 

[quickster]

My compressor won't even start when I turn the ac on. I read somewhere that might be caused by low oil or no refridge. I'm just worried about pressure in the system if I go to take it apart.

 

[Nero]

Oil won't cause the clutch to not engage. There's a pressure switch on the receiver dryer, if it doesn't detect pressure, it won't turn the pump on. Chances your system is empty.

 

[Cant Write]

My compressor won't even start when I turn the ac on. I read somewhere that might be caused by low oil or no refridge. I'm just worried about pressure in the system if I go to take it apart.

Another thing I would do is quickly depress/release the low side Schrader valve and see if there is any pressure at all. If there is, and your system is still R12, you will want to have that evacuated before you tear stuff apart.

 

[quickster]

Hey thanks. Is the receiver dryer the can looking thing on the pass side standing up? I'll bet its empty . I'd like to be able to check the pressure, or pull a vacuum. But I don't have either of those tools to do it. Anyway to see if it's holding any pressure besides undoing a connection?

 

[quickster]

It's been converted to r134.

 

[Nero]

If it's already been converted, assuming whoever did it last time did it right... Just grab a pocket screwdriver or something and poke the Schrader valve at the service port. Wear gloves and keep your eyes clear, but if a white mist comes out, it has some of a charge. If just air, it's probably empty.
Yes the can thing is the receiver dryer.