Spring 40-50-3145

Poor spring movement or uneven tool action can point to a worn constant-force spring. The spring helps an internal part move back to its proper position after each cycle. First check for dirt, bent guides, loose hardware, and damaged parts around the spring. Match the replacement to the full nailer model and serial range because similar tools may use different spring sizes. Unload the magazine, disconnect the air supply, and press the trigger in a safe direction to release trapped pressure. Follow the service diagram closely, and keep your face and hands clear of the spring path.