F 450 2WD Super Duty V8-5.4L SOHC VIN L (2003)
5. Open the high-pressure service valve.
6. Open the special tool valves and inject the fluorescent dye into the refrigerant system.
7. Close the high-pressure service valve to allow the pressure inside the special tool to equalize with the suction side of the refrigerant system.
8. Close the valves on the special tool.
NOTE: Close the valves on the special tool while the A/C compressor is operating.
9. Disconnect the high-pressure and low-pressure service valves and remove the special tool from the vehicle.
NOTE: Leave all valves on the special tool closed when not in use.