Yet Another Air Conditioner Question 1955

[Paul Falabella]

Air Conditioner seems fine. Pressures 40/150 +/-, duct temp 39-43 degrees. Cools enough to put blower on low in 90 degree temp. Heres the question. After shutting down from a drive, a steady parade of bubbles, rear to front, are visible in the sight glass. They can be momentarily stopped by tapping on the sight glass pipe. The next day there are no bubbles, even when tapping the sight glass tube. I was think of adding another can of refrigerant, but is that necessary being system seems to be working fine? Leave it alone? Hate to upset the apple cart. 

[old-tank]

Leave it alone...all of my 55's act like that

Willie

[Paul Falabella]

Thank you sir, kinda what I figured. Almost forgot; do the blower motors need lube and if so where?

[old-tank]

No way to lube without removing and disassembling the motors.  Leave it alone and enjoy.  Winter project if you have a bad case of 'tinker-itis"

Willie

[TexasJohn55]

Paul, ideally, the condensor cools the vapor down and it becomes a liquid. You need liquid to the expansion valve where it passes thru the orifice and the pressure drop vaporizes it and gives up heat, hence cold gas in the evaporator. After shutdown, all the liquid vaporizes, hence the bubbles in the sight glass. Like the man said, it is normal.