Stellar
®
Small OTR Service Crane Owner’s Manual | Page 21
Single crane function
will not operate (will
not pressurize).
Valve section shuttle ball is
not releasing.
Locate a different valve section further down
stream from the valve section that is not
functioning. Note: Use a function other than
any rotation sections such as crane rotation,
tireman rotation, or pad rotation. Operate the
valve section or crane function further down
stream from the faulty valve section. Extend
the cylinder or cylinders until full extension
is achieved and hold. While holding that
function, operate the faulty valve section
function, then quickly release the handle
assembly of the valve section that was being
held. By pressurizing the the function further
down stream and quickly releasing the handle,
the back pressure should release the shuttle ball
on the faulty valve section. This may not work
the first time so repeat the above procedure
until the faulty function operates properly.
Vibrations and jerking
in hydraulic cylinders.
Air in cylinder.
Fully cycle the cylinder both directions (blow
past relief) to remove air from system.
The temperature of the
hydraulic oil is too low.
Perform maneuvers without loads for several
minutes to warm up the oil.
Lack of oil in reservoir.
Add hydraulic oil.
Counter balance valves are
not functioning properly.
Contact Stellar Customer Service for support.
Crane rotation is
abnormal during
operation.
Inadequate bearing
lubrication.
Lubricate gear bearing/gear box.
The truck is not on a level
surface.
Level the truck using stabilizers.
Rotation bearing is worn.
Replace with new bearing kit.
Rotation motor worn.
Replace rotation motor.
Gear bearing worn/missing
teeth.
Replace with new bearing kit.
The crane does not
lift the loads on the
load chart.
Incorrect system pressure.
Refer to crane specifications for proper relief
settings.
Crane is not receiving proper
hydraulic pressure
Check hydraulic reservoir fluid level.
Ensure dump valve is operating properly.
Verify hydraulic pump is producing proper
pressure.
The crane does not
lift the loads on the
load chart.
Crane is not receiving proper
hydraulic flow
Check hydraulic reservoir fluid level.
Ensure dump valve is operating properly.
Verify hydraulic pump is producing proper flow.
Ensure hydraulic oil is at the proper operating
temperature.