busboy:,

The amount of charge (r-12) is what "manipulates the pressure. If you have too much pressure from over charging, a clogged system or a cooling issue (ie fan clutch bad) then your ac system can over pressurize and/or overheat and blow a hose , an o-ring or usually the little lead plug on the nut on top of the receiver.


As far as r-12 goes , it is with out a doubt the best refrigerant for your truck. I have three old Toys that I maintain myself one of which is a DD and I havn't had to fix the ac for close to 10 years and it blows 38'F .

My point is , a properly installed / operating system can be hassel free for a long time and worth the extra money to put in stock parts and charge with r-12.

My suggestion for you would be to replace the dryer(filter-receiver)but only after you've done all other repairs first.If you can , borrow or rent a vacum pump and see if it will hold a STEADY reading overnight. Then recharge.

By the way , there is some new info out there that contradicts just how bad r-12 is. Many countries other than the US still manufacture it. I recently bought some in Tecate for 8$ a pound and installed it there. In the US it is still legal to reclaim, reuse ,sell and install r-12 in a properly function system if you are certified to do so. The part that pisses me off is that with all the retrofits,the demand for r-12 has gone down but shops are ripping people for up to 100$ a pound to charge.

I called my local HVAC supplier the other day and they were selling 30lb. cylinders of r-12 for right at 700$

Again, thanks for the advice folks. I actually drove a friend to get her van picked today up as it was getting the A/C worked on and got to bend the mechanics' ear for a moment. He recommended of course replacing the tweaked condensor, dryer, o-rings in between, and probably the "U" shaped line that connects them as it appears to have been bent a little as well. I inquired about the r-12/r-134 swap and he said screw both and go with something they've been using called "freeze-12". Supposedly they have been having great results with it, cools just as good as r-12, and for about $100 he would pull a vac and then charge it and oil it for me.
I might take him up on it. He also said it's a direct replacement for r-12 and there's no retrofitting involved. I surely could have enjoyed kicking that A/C on after wheelin' through the Ocala Natl. Forest this weekend, it was a hot ride in the rig back home...

Foxtrapper do you know what pressure you ended up with? I stuck with the recommended 80% of the 2 lbs of r-12, and my gauges read in the green for the correct amount of pressure, but it never gets that cold, definately not even close to the old r-12.