540G - SKIDDER, LOG 21 MAIN HYDRAULIC SYSTEM Parts group 21 MAIN HYDRAULIC SYSTEM 2160 HYDRAULIC SYSTEM . CONTROL VALVE PRESSURE AND RETURN HYDRAULICS HYDRAULIC PUMP AND RESERVOIR HOSES AND FITTINGS HYDRAULIC PUMP GASKET TO TRANSMISSION Hydraulic Pump HYDRAULIC PUMP ADAPTERS HYDRAULIC RESERVOIR AND RETURN FILTER Cold Start Dump Valve Priority Valve Select group 21 MAIN HYDRAULIC SYSTEM John Deere: 2160 HYDRAULIC SYSTEM