Examining and dismantling a defective Comet Pump driven pressure washer. Disassembly and inspection of the plunger pump onboard.

Plunger pumps are a type of positive displacement pump that work by expanding and contracting a cavity using a plunger rod. First, the cavity expands as the plunger rod moves away, which draws in fluid from an inlet valve. Then, the rod moves back towards the cavity, contracting the cavity and expelling fluid.