Rotate drive shaft by hand to insure alignment and pump looseness. Pump parts are manufactured to precise dimensions and most rigid quality control standards. The smallest foreign particle or damage in the form of a nick or gouge could jam the gears and bind the pump. Extreme cleanliness and care is essential for proper pump assembly. Teflon gears have lower life expectancy than metal gears.
High pressures accelerate pump wear and reduce service life.
It is advisable to bring the temperature up gradually. Freezing liquid in pumps can deform or damage pumps. This will inevitably cause galling or seizing of the internal parts. Always prime the pump with a clean, light lubricating oil or with liquid to be pumped. Before starting, rotate the pump by hand.