Converting from R12 to R134a

[jick.cejoco]

how about the hoses?

hoses previously used with R12 systems maybe used with R134a. new hoses made for R12 will leak if used on R134a.

to determine the high side pressure without the discharge service port, you can use an infrared thermometer on the upper tube of the condenser and compare the temperature to the pressure using the R134a pressure/temperature chart. the other way is to compare the temperature of the condenser top with the pressure/temperature dial of the manifold gauge. this will give you about 90% accuracy of the estimated pressure