Baroness LM551, Service Manual, Page: 41 / 213

Hydraulic Traveling Circuit Failure
The hydraulic traveling circuit of this equipment
is made up of a closed circuit.
In the event of failure of the hydraulic
equipment, debris and contaminant from the
faulty hydraulic equipment will circulate to
every part of the hydraulic circuit.
Since this contaminant causes damage to
other hydraulic equipment, such debris and
contaminant must be removed to prevent
failure of other hydraulic equipment.
In the event that failure of hydraulic equipment
is found, remove hydraulic hoses and piping of
the affected hydraulic circuits and clean them
well with kerosene.
Drain all the hydraulic oil from hydraulic tank
and hydraulic equipment, and clean them well.
We recommend to replace the hydraulic oil,
hydraulic oil filter, and defective hydraulic
equipment with new ones.
Replacement of Hydraulic Oil
Caution
Be careful with hot oil, which could cause
burns if it contacts your skin.
Important
In the event of contamination or failure of the
hydraulic circuit, always clean the inside of the
circuit before replacing with hydraulic oil.
Drive and maneuver the machine and warm
up the hydraulic oil.
Move the machine to level surface.
Apply the parking brake, and then lower the
operating machine to the ground.
Stop the engine, and then remove the key.
Drain the hydraulic oil from the hydraulic
tank.
Drain the hydraulic oil from the hydraulic
hoses and piping while the oil is still warm.
Check if the hydraulic tank interior and the
suction filter if attached, and clean as
necessary. 1.
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Fit the hydraulic hoses, piping, and hydraulic
fittings that have been removed.
Important
Use only the specified hydraulic oil.
Use of other hydraulic oil may lead to the
failure of hydraulic circuit.
Replace the hydraulic oil and hydraulic oil
filter.
Make sure that the traveling pedal or the
traveling lever and all the drives of the
operating machine are in neutral position.
Run the engine idle for 10 seconds, then
stop the engine and check for any oil
leakage and the condition of the hydraulic
equipment.
Perform this operation twice.
Start the engine, allow it to run idle for at
least two minutes, and then run it at
maximum speed for one minute.
Raise and lower the operating machine, and
then turn and travel.
Stop the engine, and check for any oil
leakage.
Check the amount of hydraulic oil. Add as
necessary.
Operate for two hours under normal
operating conditions.
Check the condition of hydraulic oil.
If it is contaminated, repeat the above
procedures until the hydraulic oil becomes
clean.
If no abnormality is found, operate normally
and maintain according to the maintenance
schedule.
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Hydraulic System
LM551
Hydraulic System
Page 4-3
General Inspection and Repair