Addressed no-cool complaint on a Trane XR14 system in South Plainfield. Diagnosis revealed low refrigerant charge and dirty condenser coil. Performed leak detection using Fieldpiece DR82 refrigerant detector, locating small leak at Schrader valve. Replaced valve core using Appion MegaFlow speed wrench. Recharged system with R-410A to factory specifications using Yellowjacket 42006 digital manifold. Cleaned condenser coil with Nu-Calgon Alka-Brite Plus for improved heat transfer. Replaced clogged air filter with Honeywell FC100A1037 MERV 11 filter. Post-repair testing confirmed proper cooling operation and improved system efficiency.