Genuine Makita 345982-2 — Exhaust valve. Direct-fit replacement exhaust valve used in Makita gas/cordless nailers; it seals and vents the cylinder during firing to prevent leakage and restore reliable driving power.
Fits models as listed on Makita parts diagrams: GN420C / GN900 and GN900SE. Supplied as the individual exhaust valve called out in the tool’s exploded view, so you can drop it into the same position without modification.
Notes for use: the part is the specific Makita exhaust valve called out on official Makita parts lists — a small replacement piece that resolves exhaust leakage, weak drives or intermittent firing when worn or damaged. If your nailer is showing those symptoms, replacing part 345982-2 with a genuine Makita component is the straightforward repair.
Jump straight to the Makita spare parts diagrams:
