Question On air Conditioner system older truck

In the past we used pag 100 but no longer use pag at all due to being corrosive to internals and absorbing moisture. I would use nothing but polymax2 oil in any system no matter the refrigerant. Don't accept what they offer on the shelf, ask for it or move on until you find it.

I would pull the compressor, cap the lines, drain the oil, Acquire a dipstick for york compressors. Any IH dealer should have one. Fill compressor with poly2 oil using the dipstick for proper oil level, install the compressor, evacuate and charge the system with the same amount of 134a as r12 was used before, in the neighborhood of 3.2-3.4 lbs. Your gage readings will vary depending on if you have cleaned evap, changed filter and cleaned condenser.

P.S It wouln't hurt to change the dryer while you have the system open.

 

My F-liner manual says figure 2 oz. of oil will hang in each component meaning the condenser will have 2 oz, the evap will have 2, the dryer will have 2 but you will use a new one so forget that.

I'm pretty sure I remember that right. Too lazy to look right now.

 

. You can use ester oil easy to find. If its a cci or climitech take off dump oil out these compressors have crankcase. That should get at least half oil capacity then fill compressor with about 10oz of ester. Ester is more tolerant to mineral oil. Vacuum system for 30 min. Then charge 80% of what the r12 weight is supposed to be probably around 3 lbs. So charge about 2lbs 8oz. Or until lowside begins to swet. Pressures are hard to say depending on ambient temp outside.

 

Yes if the oil has been removed you can do that

 

Not sure due to the retrofit, but most Internationals with a CCI type compressor, (like yours) had a charge of 3.5 to 4 lbs depending on the model. What are these cans you are adding? I have never used the cans, just a machine. Are those cans only 6oz of refrigerant with some oil mixed in? So if you only added 2 6oz cans you're way undercharged at this time. Not sure about your model year, but newer stuff has a low pressure switch, so if the pressure is too low due to a low charge the compressor will not come on. Basically your power flow to the compressor will go something like this, power to the compressor clutch will go through a freeze switch in the evaporator, through a low pressure switch, and high pressure switch, from the a/c controls, not necessarily in that order. I don't have diagrams for your year, but late 90's were using relays, but same principal. As long as power is getting through the pressure switches and freeze switches your system should run. Don't forget the fuses either. Sounds like your system doesn't have a leak. Your pressure readings show the compressor isn't moving anything when you apply 12 volts to it. Are you sure about the gauge readings? Sometimes the expansion valve is on the verge of getting stuck and will cause issues like this. Then once you open the system and the pressure is zero the needle valve will seat and get stuck and that's it! With a stuck expansion valve, once the compressor runs the low side drops to near zero and the high side is high since the expansion valve is stuck closed. Your case almost sounds like the compressor will not pump and the expansion valve is stuck. Did you put anything else in this system, like maybe an a/c leak repair kit?

 

I think you are right about it being near the fire wall, sorry those ol' girls are from before my time! If your low side has all the pressure and you jump power to the compressor it should suck from the low side and pump it all to the high side even if the expansion valve is stuck. For some reason the compressor can't suck from the low side. Are you measuring the high side at the receiver/drier?