This brake pump is a slave cylinder that converts hydraulic pressure from the clutch pedal into mechanical force to disengage the clutch on a self-propelled forage harvester. It is mounted in the brake and drive system, where its piston actuates the clutch release mechanism when fluid is pressurized. A failing pump will cause a soft or non-responsive clutch pedal, making gear engagement difficult or incomplete. The pump is designed for use with DOT-3 or DOT-4 brake fluid. On reinstallation, bleed the system fully to remove air from the hydraulic circuit.