18-4257 SIERRA BLACKSTEEL PLUG PIPE PLUG

# 18-4257 SIERRA BLACK STEEL PLUG Durable black steel plug engineered for marine engine applications requiring reliable port closure and system integrity. This OEM Sierra component seals openings in engine blocks, manifolds, and accessory housings, preventing coolant leakage and maintaining proper fluid circulation. Manufactured from corrosion-resistant black steel to withstand saltwater exposure and thermal stress. Precision-threaded design ensures secure installation without stripping or leaking. Essential for engine assembly, repair, or restoration work on Sierra-equipped marine powerplants.