Unit had a refrigeration leak. Fixed leak and recharged unit. Suction pressure running into a vacuum. Then I hear solenoid turn on and pressure rises then goes into a vacuum again. Changed solenoid coil, same issue. Solenoid is switching to RC and FC. Note: Used digital scale for refrigerant. Thank you
Answer Hello Ralan,
When the low side pressure drops into a vacuum it is an indication of a restriction in the sealed system. This shows that the Freon is not able to return to the compressor as quickly as it is being pumped away from it. Since you did not mention replacing the filter/drier, my first suspicion is a restriction in the filter/drier end of the cap tube, normally within the first couple of inches.