MAINTENANCE 8. Remove the cover bolts (4) of the two filter covers (3) at the top of the tank and remove the covers. 9. After removing the spring (5) and the bypass valve (6), remove the element (7). 10. Before cleaning the element, ensure that no foreign material exists inside the tank. 11. After installing the new element, install the bypass valve (6), the spring (5), and the cover (3). If the O-ring for the cover is damaged or deteriorated, replace it with a new part. 12. When installing the cover bolts, push down on the cover and tighten the bolts evenly. 13. Add hydraulic oil through the oil filler port (F) to the specified level and install the cap.
For details of the oil to use and refill capacity, See 20 FUEL, COOLANT AND LUBRICANTS ACCORDING TO AMBIENT TEMPERATURE on page 3-9. 14. Check that the hydraulic oil is at a standard level. See 24.5 EVERY 100 HOURS SERVICE on page 3-38. 15. Run the engine at low idle to bleed air from the hydraulic tank. Extend and retract the steering, bucket, and lift arm cylinders four to five times. Be careful not to operate the cylinder to the end of its stroke; stop the cylinder about 100 mm (4 in.) before the end of the stroke. WARNING Operating the engine immediately at high speed or the cylinder to the end of its stroke could damage the piston seal. WA450-3MC 3-56