24. SERVICE PROCEDURE Procedure for bleeding air Bleed the air from the various components in the order below ( 1 ). 1. Bleeding air from pump 1) Loosen air bleed plug 1 and check that oil oozes out from the air bleeder. 2) If no oil oozes out, remove the drain hoses from the pump case, and add hydraulic oil through drain port 2 to fill the pump case. Oil will come out when the drain hose is re- moved, so secure the hose mouthpiece at a position higher than the level of the oil in the hydraulic tank. AM092590 3) After completing the air bleed operation, tighten air bleed plug 1 and install the drain hose. NOTICE If the drain hose is installed first, oil will spurt out from plug hole 1 .
If the pump is operated without filling the pump case with hydraulic oil, abnormal heat will be generated and this may cause premature damage to the pump. 2. Starting engine Start the engine. For details, see “12.2 STARTING ENGINE”. Run the engine for 10 minutes at low idling, then go on to the next operation. 3. Bleeding air from cylinders 1) Run the engine at low idling, and extend and retract each cylinder 4 – 5 times. Do not operate the cylinder to the end of its stroke. Stop at a point approx. 100 mm before the end of the stroke. 2) Next, operate each cylinder 3 – 4 times to the end of its stroke.
3) Finally, operate each cylinder 4 – 5 times to the end of its stroke to completely remove the air. NOTICE If the engine is run immediately 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. 3-70