Komatsu SK820-5 turbo, Operation & Maintenance Manual

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TROUBLESHOOTING
150
3.15.4.4 HYDROSTATIC TRANSMISSION
TROUBLE CAUSE REMEDY
Machine moves neither forward, nor
backward:
• Oil level insufficient.
• Suction filter clogged.
• Faulty flexible coupling.
• Max. pressure valves faulty or dirty.
• Positioning hydraulic connection
interrupted.
• Travel motor faulty.
• Top up.
• Change.
(•) Change coupling.
(•) Clean or change valves.
(•) Restore connection.
(•) Repair or change.
Machine moves with delay - Abnormal
noise
• Oil level too low.
• Presence of foam.
• Suction pipe tightness.
• Suction filter clogged.
• Fuel supply max. pressure valve
faulty.
• Travel motor faulty.
• Top up.
• Use the recommended oil.
(•) Check and eliminate leakage.
• Change.
(•) Disassemble and clean or change.
(•) Repair or change.
Traction force in the two travel directions
is insufficient
• Endothermic engine does not reach
max. speed.
• Auxiliary fuel pump (gear pump)
faulty.
• Max. pressure valve setting incor-
rect.
• Connection to servo control faulty ñ
lever angle incorrect.
• Pressure relief valve setting incor-
rect.
• Excessive oil temperature.
• Travel motor faulty.
(•) Change diesel oil filter and check
injection pump.
(•) Repair or change.
(•) Set.
(•) Restore connection ñ shift lever to
correct position.
(•) Set.
• Check oil level and clean exchan-
ger.
(•) Repair or change.
Traction force is insufficient in one direc-
tion only
• Endothermic engine strongly over-
loaded.
• Incorrect setting of the max. pres-
sure valve relevant to that direction.
• Reduce loads due to lifting.
(•) Set valve.
Oil overheating
• Oil level too low.
• Exchanger clogged or dirty.
• Unsuitable oil.
• Suction pipe tightness.
• Setting and operation of the max.
pressure valves.
• Travel pump faulty.
• Pressure relief valve with high set-
ting.
• Travel motor faulty.
• Top up.
(•) Check and change if necessary.
• Use the recommended oil.
(•) Check and eliminate leakage.
(•) Check setting, repair or change.
(•) Repair or change.
(•) Set valve.
(•) Repair or change.
Machine does not reach max. speed se-
lected
• Suction filter clogged.
• Endothermic engine does not reach
max. speed.
• Auxiliary pump (gear pump) faulty.
• Pilot pressure insufficient.
• Pressure relief valve setting incor-
rect.
• Change.
(•) Change diesel oil filter and check
injection pump.
(•) Check delivery, repair or change.
(•) Set.
(•) Set to rated value
Machine decelerates discontinuously:
• Mechanical connection with servo
control lever too hard.
(•) Check if rotation is smooth.