Lull 944E-42 Service Manual - Manual (Page 58)

Boom
3-28 944E-42
3.9.3 Hydraulic Hose Replacement
3.9.4 Hydraulic Hose Replacement - Step 1
1. Clear area of any unnecessary personnel.
2. Block all four wheels.
3. If the load is in a position where it can removed
safely, completely remove the load from the carriage,
otherwise leave the load in place.
4. Temporarily block up or support the outer boom.
5. Replace the failed hydraulic line with a new part.
• Boom Extend line - Extend Cylinder to Block (1)
• Boom Retract Line - Extend Cylinder to Block (2)
• Boom Extend line - Block to Frame Bulkhead (3)
• Boom Retract Line - Block to Frame Bulkhead (4)
• Boom Lower Line - Lift Cylinder to Block (5)
• Boom Lift Line - Lift Cylinder ot Block (6)
• Boom Lower Line - Block to Frame Bulkhead (7)
• Boom Lift Line - Block to Frame Bulkhead (8)
6. Check the hydraulic oil level, add oil if needed.
7. Remove the blocking or support from the outer
boom.
8. Return to cab, fasten seat belt and start engine.
9. Tilt the carriage upward, if necessary, for clearance
before retracting the boom.
10. Slowly retract the boom.
11. Slowly lower the boom and ground the carriage.
12. Shut off engine.
13. Completely remove the load from the carriage, if not
previously done.
14. Return to cab, fasten seat belt and start engine.
15. Cycle the lift/lower and extend/retract cylinders
several times to bleed air from the system. Check for
leaks.
16. Recheck hydraulic oil level. Add oil if necessary.
NORMAL STEPS
HYDRAULIC LINE THAT FAILED
Follow this step if parts are available Follow this step if parts are not
available
BOOM LIFT LINE
(Lift Cylinder to Block or Block to
Frame Bulkhead)
STEP 1 STEP 2
BOOM LOWER LINE
(Lift Cylinder to Block or Block to
Frame Bulkhead)
STEP 1 STEP 1
BOOM EXTEND LINE
(Extend Line to Block or Block to
Frame Bulkhead)
STEP 1 STEP 2
BOOM RETRACT LINE
(Extend Line to Block or Block to
Frame Bulkhead)
STEP 1 STEP 1
OU1061
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