The Makita 419004-5 is a genuine replacement piston designed to restore the impact mechanism in Makita HR4011C and HR4001C rotary hammers. Precision-machined to Makita's exact tolerances, this metal piston maintains the compression and smooth reciprocation essential for consistent hammering performance. It ensures the air-driven hammer action responsible for delivering striking power in concrete drilling and masonry chiselling is fully restored after wear. Fitting a replacement piston is the correct course of action when a rotary hammer begins showing signs of reduced impact energy, irregular blows, or inconsistent output. As a genuine Makita part, no modifications are required — it is a direct-fit component that reinstates the tool's original sealing and reciprocation characteristics. This piston is well suited to contractors and tradespeople carrying out preventative maintenance or repairing a tool that has seen heavy site use. Installing it into a clean, well-lubricated cylinder supports a longer service life and helps reduce vibration and erratic impact associated with a worn component. Features and Benefits: • Genuine Makita part (419004-5) for assured compatibility with HR4011C and HR4001C • Precision-machined metal construction engineered to Makita's exact tolerances • Restores hammering power, blow consistency, and overall tool efficiency • Direct-fit replacement requiring no modifications for straightforward maintenance • Helps reduce vibration and erratic impact caused by piston wear • Supports extended service life when fitted in a clean, well-lubricated cylinder • Suitable for preventative maintenance or repair following heavy professional use
