Questions and Answers

1957 Chevrolet Air Conditioner Q. I have installed a vintage air/heating system on my 1957 Chevrolet and while adding R134a to it, I noticed that the low side pressure goes extremely high when the air conditioner is turned off. I lost one charge of freon already through the high pressure hose fitting. What does this indicate and what should I tell the HVAC person so that it sounds like I know what I'm talking about? Thanks, Steve

A. If you don't know low from high pressure you should just have someone take a look at it. Maybe you hooked up the hoses wrong on the system? Charge fittings wrong? A standing pressure on A/C with R134a can be 45 to 85psi without the system running. This should be the same on both low and high sides.