Hotsy pumps are manufactured with a Plunger Oil Seal to keep the high pressure water from mixing with the pump oil found within the crankcase, or pump body. These plunger oil seals slides onto the pump piston and sits behind each ceramic piston sleeve. If damaged or worn, the water from the manifold may contaminate the oil, reducing pump lubrication, resulting in either extensive damage or possible Hotsy pump replacement. Milky or caramel-colored pump oil is typically a sign of a failed plunger oil seal.
