Unscrew the oil drain plug at the bottom of the pump casing to remove old oil and accumulated fuel dilution.
An injection test bench spins the pump at exact RPMs while measuring the precise cubic millimeters of fuel output from each cylinder into graduated cylinders. Balancing these cylinders perfectly is critical to preventing engine damage. bosch pes4a manual
Proper lubrication is the single most critical factor in extending the lifespan of a PES4A pump. Checking and Changing Pump Oil Unscrew the oil drain plug at the bottom