This hydraulic gear pump is the original equipment unit for the tractor's hydraulic system. It draws fluid from the reservoir and delivers pressurized flow to the control valves, which then direct it to the implement lift cylinders and remote couplers. A worn pump produces a characteristic whine under load and results in slower implement response times. The original pump's internal clearances are set to match the housing bore of the host tractor, ensuring the volumetric efficiency that the system's relief valve and flow divider were designed around. When replacing, transfer the inlet and outlet fittings from the old unit and prime the pump before starting the engine to avoid dry-running damage.