MAINTENANCE 9. Remove mounting bolts (6) of the cover (5) at the top of the tank, then remove the covers. REMARKS: The cover is spring-loaded and could pop off from the force of spring (7), so keep the cover pushed down while removing the bolts. 10. Remove spring (7) and bypass valve (8), then remove element (9). 11. Check that there is no foreign matter inside the tank before cleaning it. 12. Install a new element, then install bypass valve (8), spring (7), and cover (5). If the O-ring of the cover is damaged or deteriorated, replace it with a new part. 13. When installing the cover bolts, push down on the cover and tighten the bolts evenly. 14.
Add hydraulic oil through oil filler port (F) to the specified level, then install cap (F). For details of the oil to use and refill capacity see “20.1 PROPER SELECTION OF FUEL, COOLANT AND LUBRICANTS” on page 3-10. 15. Check that the hydraulic oil is at a standard level. See “24.5 EVERY 100 HOURS SERVICE” on page 3-46. 16. Run the engine at LOW idle and extend and retract the steering, bucket, and lift arm cylinders 4-5. times. Be careful not to operate the cylinder to the end of its stroke (stop approximately 100 mm (4 in) before the end of the stroke).
WARNING 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 could cause damage to the piston packing. 17. Next, operate the steering, bucket, and lift arm cylinders to the ends of end their strokes 3-4 times, then turn OFF the engine and loosen bleed plug (10). Run the engine at low idle to bleed the air from the hydraulic tank. After bleeding the air, turn OFF the engine and tighten plug (10) again. 3-70 WA320-3MC