GENERAL / Bleeding Air from Hydraulic Circuit BLEED AIR FROM THE HYDRAULIC SYSTEM Bleed air from the hydraulic system as follows when hydraulic oil has been drawn, the suction filter and suction pipe have been replaced, or the pump device, cylinders have been removed/ installed. INPORTANT: If air is accumulated inside of the pump and if the engine starts in lacking of hydraulic oil, the pump may be damaged. Bleeding Air from Pump. Remove the air bleed plug on top of the pump. Add hydraulic oil to the pump. After the pump is filled with hydraulic oil, temporarily tighten the plug. Then, start the engine and run it at slow idle speed.
Slightly loosen the plug and bleed air from the pump until hydraulic oil comes out from the gap. After bleeding all air, securely tighten the plug. INPORTANT: If air is accumulated inside of the cylinder and if the cylinder is operated suddenly in lacking of hydraulic oil, the seal may be damaged or the cylinder may seize. Bleeding Air from Hydraulic Circuit After refilling hydraulic oil, start the engine. While operating each cylinder evenly, operate the machine under light loads for 10 to 15 minutes. Slowly start each operation (never fully stroke the cylinders during initial operation stage).
As the pilot circuit has an air bleed device, air in the pilot circuit will be bled while performing the above operation for approx. 5 minutes. Reset the front attachment in position for checking hydraulic oil level. Stop the engine. Check hydraulic oil level. Replenish hydraulic oil if necessary. W1-4-2