Any A/C guys out there???

I'm not an A/C guy. Here's a brief history.....

Truck was wrecked a while back. Receiver/drier tube was damaged, all freon leaked out. It was late summer so I didn't worry about A/C Started repairs following summer, flushed out condenser since it had been open, installed new receiver/drier and left alone when i found out price of r-12. Finally got back around to it yesterday. Decided to retrofit to R134a, bought kit with fittings, oil, etc. Removed compressor and drained all oil, replaced seals, installed new fittings and vacuumed down for approx 40 minutes. Did get considerable water out of system. Started filling with R134a, air inside cab was getting cool after one can. Then I noticed HIGH SIDE pressures getting really high! (350 psi and beyond) When I closed off freon, the low side was actually below zero (vacuum) Does this Mean I still have moisture in system and is freezing up? Air in cab stopped cooling by the way. It was weird have a vacuum on the low side and way too high on the high side.

ANY HELP APPRECIATED!!!

sounds like maybe moister in system freezing and pluging expansion valve that would account for your readings.

This is an 89 Toyota King-Cab 4X4. Where is the Expansion valve and how do I get to it? I'll probably just go ahead and replace it and the receiver/drier. Please don't say it's behind all that crap in the dash! (Like I said, I'm not an A/C guy!)

Yep, its behind all that crap!
Good luck, its quite a pita, you may have to pull the whole
thing with the hose if its rusted and you can't remove it.

You should have kept it r12, its not that expensive, plenty of the stuff on ebay. Also I have had good results with envirosafe freon substitute, its hydrocarbons.

Probably going to have to evacuate it for 24 Hrs..
and change driers a time or two also.