Found Walk-In Cooler Box temperature 11F sight glass full low side 17psi high side 365psi blew out condenser coil with compressed air loaded with dust from dryer vents. Sight glass emptied out high side dropped to 217psi. Found liquid line serve cap cracked and Schrader leaking. Tightened Schrader and replaced cap with brass. Recharged unit. Temperature dropping at 3F will take some time due to defrosted product. Unit cooling properly.