How To Install or Replace a Bernard Power Pin on a BTB MIG Gun
 

1. Remove nozzle, contact tip, and gas diffuser / retaining head and lay cable straight. Using a 10 mm wrench, turn liner lock counterclockwise until it is free from the power pin. Remove liner from gun assembly.
    
2. Remove the screw and assembly from rear strain relief and slide rear strain relief back over power pin. Position control lead wires as necessary to avoid damaging them.
    
3. Use wrenches and rotate power pin in a counterclockwise direction to remove it from the adaptor block.
    
4. Thread new power pin into adaptor block and use wrenches in a clockwise direction to thread power pin into adaptor block. Torque to 13 ft.-lbs. (17.6 Nm).
    
5. Slide rear strain relief over power pin and locate onto adaptor block, aligning flats and screw hole. Secure with screw,  position control lead wires in cutout on side of strain relief, close strain relief top and secure assembly by rotating clockwise 1/4 turn.
    
6. Reinstall liner by following the steps listed in #1 in reverse order.