Re 1999 Avalon AC performance is borderline...lots of bubbles in sight glass and 46-48 low temp coming out of center vent. Doors closed, windows down, recirc on, 1800 rpm, 86 degrees and humid. Put on the gages. High side looks ok, around 225. Low side is low, around 25 but bigger problem is low is not stable. It will hold 25 for 15-30 seconds then start pulling down. When fans kick into hi speed, drop accelerates and low side pressure switch kicks off compressor around 15. I would say I have a restriction in the orifice. Also, when I turn off car, it takes a long time for pressures to equalize. After standing there for several minutes, high side was still 150. Definitely not going to put serious money into this almost 22 year old car plus at 71, I really don't feel like doing a major ac overhaul even though I have all the tools and know how. Could I be missing something easy? Thanks.