[futuresoptions]

I have seen something as odd as a liquid line filter fail and begin to clog the TXV and I have seen in situations like yours where the TXV has failed or to where the fixed orifice was sized incorrectly to the condensor (especially in a mis-matched system)... alot of factors go into a system that has never worked correctly... one has to be there to look at the piping etc... to find clues to what is really going on.. IMHO there should never be bubbles in a sight glass if everything is sized correctly... with the pressures you gave I would think of low charge, but I have seen units with bad valves show the same thing... if the TXV is adjustable, it could use some tweeking, if it never worked correctly, you could have had defective parts from the very beginning.... just hard to trouble shoot a never worked situation from cyber space...