What type of oil / lubricant is used on the hydrostatic test pumps?
Diaphragm Hydrostatic test pumps use oil in the engine, in the gear reduction unit, and in the pump itself. 30 weight motor oil is used for the engine and pump. The gear reduction unit uses 90 weight gear lube.
**Piston Pumps only use oil in the engine. (30 weight motor oil.)