Lull 944E-42 Service Manual - Manual (Page 57)

3-27 944E-42
Boom
3.9 EMERGENCY BOOM LOWERING
3.9.1 Loss of Engine Power or Hydraulic
Pump Failure
Note: In the event of total loss of engine power or
hydraulic pump failure with an elevated load, the
situation must be properly evaluated and dealt with on
an individual basis. Contact your local Authorized
distributor for specific instructions for your particular
situation.
Note: Refer to Section 5.7, “Towing a Disabled
Machine,” if needed.
In any event, the machine should be secured until the
situation has been properly evaluated. Secure the
machine by following the procedures below.
1. Clear the area around the machine of all personnel.
2. Block all four wheels.
3. Section off a large area under the boom with string
or tape to restrict any personnel from entering this
potentially dangerous area.
4. Temporarily block up or support the outer boom so
that it cannot be lowered.
5. 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.
6. Place an Do Not Operate Tag on both the ignition
key switch and the steering wheel, stating that the
machine should not be operated.
3.9.2 Hydraulic Line Failure
In case of hydraulic line failure, there are step-by-step
procedures available to assist you in safely retracting and
then lowering the boom. Read this section from start to
finish before performing any of these procedures so you
fully understand the process and danger involved. If you
are unsure about any part of these procedures contact
your local Authorized distributor for specific instructions
on your particular situation.
Note: For boom retract and lower, the hydraulic lines
MUST be replaced, then retracted and lower the boom in
it’s normal fashion.
In any case of hydraulic line failure, it is critical to correctly
identify which hydraulic line has failed. Identify the
hydraulic line that has failed and use the table Section
3.9.3, “Hydraulic Hose Replacement,”on the following
page to determine which step to follow to retract and
lower the boom.
The hydraulic lines are:
• 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)
WARNING
DO NOT get under a raised boom unless the boom is
blocked up. Always block the boom before doing any
servicing that requires the boom to be up.
WARNING
Be aware that the boom must first be retracted and
than lowered to avoid machine tipover.
OU1061
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