Caterpillar 6J-9354 Piston Seal

The Cat 6J-9354 Hydraulic Accumulator Seal is a genuine Caterpillar two-piece piston-seal assembly (piston ring plus expander) engineered to prevent oil transfer between the rod end and cap end of hydraulic cylinders. This piston-seal design functions within Caterpillar hydraulic systems to help maintain cylinder integrity and minimize cross-contamination between cylinder chambers. Cat lists compatibility for a range of machines and configurations, including models such as 615, 615C, 621, 621B, 621E, 623, 623B, and 623E, among others in the same family; for an exact fit, verify the part against your machine model and cylinder specifications. Available through the official Cat Parts Store under part number 6J-9354, this seal embodies Caterpillar’s standard approach to hydraulic cylinder sealing where a two-piece piston-seal assembly preserves hydraulic circuit efficiency and reliability.