Something for people to look at if they are having similar air conditioner issues.

My problem was I was losing the refrigerant charge every 2 or 3 months, very slowly. It seemed to accelerate when the truck was not driven regularly. I would simply drop it by the shop and they would re-charge. I figured my son's truck being a 1998, I would need to plan on replacing the entire a/c system before selling it. In Texas, you HAVE to have a/c.....Period!

So I bought some decent a/c gauges in preparation for working on the system. Before going full bore changing parts, I installed a can of freon myself with the dye in it. I noticed that the low pressure port (the one on the dryer against the firewall) did not have a cap, and the high pressure cap did not seem to fit correctly. Bought new caps and recharged the system. It was used a few times over the next month, but mostly parked. I went out to drive it and the a/c was weak. A day or so later, I removed the caps to hook up my gauges and I get a rush of air as I am removing the low pressure cap . And the cap has the green dye all over it . Long story short....the schrader valve on the low pressure port was leaking.

Be warned, there are a couple different schrader valves that could be in 1998 models due to two different dryer assemblies. I bled the system almost all the way down via my gauges first (less than 25 psig). I then completely removed my old schrader, took a picture, then re-installed. I got the correct valve and swapped them out. My neighbor had a vacuum pump, so I pulled a vacuum for an hour or so, recharged, and have had a very strong A/C since.

I waited almost two months to declare success, so maybe this will help someone else.

 

Thanks for the info. I'm sure it will help others at some point.