Charging A/C problem

2007 International 9400i
VIN: 7C532829

I've charged the A/C on this truck before, and everything went normal. About six months later, I popped my hood and noticed greenish oil blown onto the airbox. I thought it was antifreeze at first, but it smelled funny. I realized the A/C line going from the compressor to the condenser was leaking, and even bubbling out the leak.

So I replaced the line, vacuumed the system, and started charging.

Right off the bat the high side went to almost 300 psi. Truck wasn't wanting to take freon either. After the low side got to about 70 psi, the compressor clutch engaged. Low dropped to 40 psi, and high went up to 350 psi immediately. I figured this behavior would stop once I got more freon in the system.

As I'm doing this, and waiting for the clutch to engage each time, I'm noticing the high side slowly dropping, and the low side slowly increasing, and the low side pressure would be higher every time the clutch engaged until the low side was consistently over 110 psi, with the high side sitting at about 290 psi. This is with about 18 oz of freon in the system.

I let the can sit about five minutes, and when I checked it, the low side was pegged, and the high side was sitting at about 300 psi. I shut off the truck, bled off the can to a safer pressure and removed it. Then I bled off the low side to about 70 psi. After that, I could sit there and watch the low and high side mixing as the high side was slowly dropping, and the low side was increasing until they would equalize.

WTF is going on here?

 

Last time, I could sit a can of freon there on the step, and it would take it in so the can would frost over and I could see the current level in the can. This time around, it won't take freon, or even make the can cool, but the low pressure side will gradually go over 100 psi.

When the compressor kicks on, it only clicks on and clicks right back off. It won't stay on. At that point, I can shake the can and get it to take freon. (I can see it in the sight glass on the gauges) It will take freon for a few seconds, and then quit. Took me two hours of messing with it just to get 1.5 cans in there before I gave up.

 

I vacuumed it for several hours, and it held at 29.5.

No, I didn't mess with the oil.

I didn't. But I'm going to put a drier and expansion valve on it. Once I open it again, I'm going to blow air through everything too before I put it back on the vacuum.