3720 A/C 1-1 DT check having coolant fau ~~~~~ 3720 A/C 1-1 DT check having coolant fault.  3720 A/c 1-1 found LP = 10 psi, HP = 50 psi. Charged in freon to LP = 40 psi, HP = 125 psi. No leakage found on A/c pipings. Monitor for 2 hrs - OK.  Aminur/Azmi 44416