Hagen Brothers farms,Goodrich ND | Sounds like your refrigerant charge is gone, system is empty with only 30 psi. When the compressor comes on, it pulls all the refrigerant out of the low side and pumps it into the high side. When the compressor is turned off by the low side pressure switch, refrigerant leaks back into the low side until the pressure switch closes and starts the compressor . and the cycle repeats.
You need to get a set of gauges on there that reads both low and high side pressures. Should be 28-30 psi on the low side WITH THE COMPRESSOR RUNNING, and 125 or more high side pressure depending on air temp.
The hissing sound sounds like a leak that must be fixed before any refrigerant will stay in the system. |
Freightliner A/C diagnosis
