Found Walk-In Freezer box temp 39 degrees. Sight glass empty and has leak dye in system. Charge with 4lb 8ozs r404a to full sight glass. Pressures ok. Leak checked and found all joints have been soft soldered. Found leak at suction line connection to coil. Leak detector is also sounding in and around evap coil but could be due to suction leak. Will need to replace line set and hold nitrogen on system to see if any more leaks are present. Will estimate repairs. Charge on system may not last a week.