Refrigerant Charge Check
Note that there are two types of receiver/dryer; one equipped with sight glass and the other without sight glass.
If sight glass is not provided, perform following "Performance Test" to check if refrigerant is properly charged or not.
If sight glass is provided, perform the following procedure.
Run engine at fast idle, and operate A/C at its max. cooling capacity for a few minutes. Then, look at the sight glass on receiver/dryer to check charge of refrigerant.
Use the given table when checking charged state of refrigerant and correct it as necessary.