The bumper is what stops the piston once it has fired and traveled down to the bottom of the cylinder. It protects the piston/driver so that it does not contact the metal body of the nailer. Bumpers deteriorate over time, and if the wrong pneumatic lubricant is used. Be sure to keep the nailer clean and check the bumper to confirm it hasn’t chipped or broken apart, as it can damage other components.
This item fits the following models:
3-Nailer Combo Kit w/ Accessories
3-Nailer Combo Kit
1/4" x 50 Ft Noodle Air Hose with Coupler and Plug