If the hydraulic oil or hydraulic pump is replaced, or the suction hose of the pump is removed, the operator must exhaust the air in the pump casing before starting the engine, as shown in Figure 3-21. The exhaust procedure is as follows.
① Add hydraulic oil to the specified position
② Open the leakage port at the top of the pump.
③Inject hydraulic oil through two oil ports to fill the pump casing
④ Tighten the plugs at both ends to unload the pump when the engine is idling.
⑤ Slightly loosen the plugs at both ends to allow the air in the pump casing to discharge. ⑥ After confirming that the air has been discharged, tighten the plugs at both ends.
[note]
①If there is air in the pump casing, there will be danger when the pump runs. If the hydraulic oil or pump is replaced, or the suction hose of the pump is removed, the air in the pump casing must be exhausted.
② The exhaust of the hydraulic pump must be carried out when the engine is idling and the pump is unloaded. When the engine is running at high speed or when the pump is under load, air may enter the pump and cause damage.
