24. SERVICE PROCEDURE Air bleeding procedure Follow steps 1 to 7 to bleed the air. 1. Bleeding air from pump 1. Loosen air bleeder plug y , and check that oil oozes out from the air bleed plug. 2. If oil does not ooze out from the plug, remove the drain hose from the pump case, and add oil through drain port x to fill the pump case with hydraulic oil. Oil will come out from the drain hose when it is removed, so secure the mouth of the hose at a place higher than the oil level inside the hydraulic tank. 3. After completion of the air bleed operation, tighten the air bleed- ing plug y , then install the drain hose.
NOTICE If the drain hose is installed first, oil will spurt out from the hole of plug y . If the pump is operated without filling the pump case with hy- draulic oil, abnormal heat will be generated and this may lead to premature damage of the pump. 2. Starting engine Start the engine according to 13.2 “ STARTING ENGINE” keep running the engine at low idling for 10 minutes, and carry out the following proce- dure. 3. Bleeding air from cylinders 1. Run the engine at low idling, and extend and retract each cylin- der 4 - 5 times without operating it to the end of its stroke. (Stop approx. 100 mm (4 in) before the end of the stroke) 2.
Next, operate each cylinder to the end of its stroke 3 - 4 times. 3. After this, operate each cylinder 4 - 5 times to the end of its stroke to completely bleed the air. NOTICE If, at first, the engine is run at high speed or the cylinder is operated to the end of its stroke, the air inside the cylinder may cause damage to the piston packing or other parts. PC450-ENG 3-76