Patent ID: 7517200

Claim:
A method of operating a pump, comprising: moving a plunger within a pumping chamber from a second end position to a first end position to draw a fluid into the pumping chamber; moving the plunger from the first end position to the second end position to pump the fluid through a spill passageway; blocking the spill passageway to build pressure within the pumping chamber; passing the pressurized fluid through a high-pressure outlet during movement between the first end position and the second end position, the passing of pressurized fluid through the high-pressure outlet terminating before the plunger reaches the second end position; moving a spill valve member from a first spill valve position against a spring force to a second spill valve position and holding the spill valve member in the second spill valve position with fluid pressure to block the spill passageway; holding the spill valve member in the second spill valve position with fluid pressure; and moving an outlet check valve from a second outlet check valve position against a spring force to a first outlet check valve position with fluid pressure to pass the pressurized fluid, wherein the spring force acting on the outlet check valve is greater than the spring force acting on the spill valve member.