MAINTENANCE 4.13 EVERY 2000 OPERATING HOURS OR YEARLY HYDRAULIC SYSTEM - CHANGE OIL, REPLACE SUCTION STRAINERS AND PULSATION DAMPER Vent Hydraulic pumps 1. Open vent plug (13), illust. Z 22513 on the pump suction port of all six main pumps. 2. As soon as bubble free oil flows out, tighten the vent plug (13). 3. Open vent screw on secondary pumps (8 and 9), illustration Z 21171. Close vent screw as soon as bubble free oil flows out. 4. Open vent plug (13) on the pump suction port of the piggy- back gear pumps and wait until bubble free oil flows out then tighten the vent plugs (13). 5. Check hydraulic oil level and the whole hydraulic system for leakage.
Check the Oil level in all six Main Pump Housings (I - VI), illust. 21171: 1. Remove leakage oil return line from port (15). The oil level in the pump housing should reach the lower edge of port (15). 2. If necessary add hydraulic oil up to the lower edge of the filler opening. 3. Connect leakage oil return line to port (15). NOTICE Make sure the main pump housings are correctly filled, oth- erwise the pump drive shaft bearings could be damaged due to lack of lubrication. 449