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$