Before putting a hydrostatic pump back into operation, the hydrostatic pump should be filled with hydrostatic fluid. This should be performed when installing a new hydrostatic pump or a pump that has been disassembled.
Starting a hydrostatic pump dry may cause premature wear or permanent pump damage.
Under normal operation, the charge pump will keep the hydrostatic pumps filled.
Filling the hydrostatic pump is best done by removing a plug at the top of the hydrostatic pump. A clean funnel should be used to avoid washing contaminants into the hydrostatic pump. The goal is to fill the hydrostatic pump as much as possible before start up.
Remove the air bleed plugs (Item 1) [Figure 30-51-14].
BEFORE START UP: Fill one of the air bleed ports with new hydraulic oil until the hydraulic oil flows out of the other air bleed port. This will remove trapped air in the hydrostatic pumps before start up.
Assembly: Tighten plugs to 18 ft.-lb. (25 N•m) torque.