So we got home to Ft. Lauderdale after a two week road trip to Dallas and back. The 'vette sat in our garage over two weeks and the day after I got home I took it for a spin. Suddenly I noticed A/C blowing warm air...so I added a can of R-134A and everything was fine. Next day...same thing...so I have a leak. I noticed oil around the tube fitting joints just outside the evaporator. Trip to NAPA for O rings and an orifice tube. Took it apart...back together...evacuated...Damn...not holding vacuum. Next I replaced the high and low side Schrader valves and pulled it down to -29.5" Hg. Still won't hold...Damn It !!

OK...so now my sweet wife is seeing my frustration and after explaining the whole process to her (ok...she has been with me during the solution of many Mechanical Engineering problems) she looked at me and said "Occam's Razor" ...the simplest solution is usually the correct solution.

I drank a cold one and looked at the connections at the evaporator housing....DING DING DING PHUCKIN DING!!! The damn pressure switch !! Sure as hell...pulled it out and it was cracked. Trip back to NAPA this morning...do the switch...pull it down...holds 29.5" of vacuum...put 2 lbs of 134A in...and WTF...29* air from all the vents on the inside air setting !!!

Lesson learned...don't over look the obvious!!

 

 

Good info - thanks for sharing.