Caterpillar 570-1981 Hydraulic Stick Cylinder Assembly

The 570-1981 Cylinder GP-Stick is a double-acting hydraulic cylinder designed for the stick (arm) function on Caterpillar 390 series large hydraulic excavators. It features a 220 mm (8.7 in) bore diameter and 2262 mm (89.1 in) stroke length. The assembly is compatible with serial number prefixes HJD1-UP and GAY1-UP on 390F L models powered by the Caterpillar C18 diesel engine. This cylinder forms part of the 362-6005 Cylinder & Seal GP-Stick group. Constructed from high-strength alloy steel with precision-honed internal surface finish for optimal seal life. The piston rod undergoes induction hardening and chrome plating to resist wear and corrosion in abrasive mining and quarry environments. Sealing system utilizes OEM-specification polyurethane and PTFE composite seals rated for 35 MPa (5075 psi) system pressure. Mounting dimensions conform to Caterpillar SIS specifications for direct bolt-on installation.