I'm fairly sure that the system is clogged from what I'm seeing from the gauges. Plus it's fully charged and pumping but blowing hot air. The high side is getting way way to high. I purchased a new orifice tube. I haven't worked on this particular truck before. It's my dad's 98 GMC 1500. At least I think it is. I still need to pick it up sometime this week. Where the heck is the orifice in this truck? I've always worked on cars with expansion valves up in the dash. Any info would be great. Thanks.

Robert