TROUBLESHOOTING
TRAVEL MOTOR
5
TRAVEL MOTOR “4. Disassembly and assembly, Travel motor”
Hydraulic motor Symptoms Motor fails to start
Major causes Remedies • All the devices other than the motor and the • Check whether the specified pressure is generated in the inlet port, and then reduction gears are not working correctly check and repair each device. • Pressure oil is not flowing properly due to ab- • Replace the abnormally worn out part(s). normal wear of the motor’s sliding part • Motor is faulty, as its main components are • Replace the damaged part(s). damaged Rated speed cannot be • Specified volume of flow is not supplied to • Check whether the specified pressure the motor due to the faulty oil pump is generated in the inlet port, and then obtained check and repair each device. • Motor volume efficiency becomes low • Check if there is abnormal wear on the sliding part; if so, repair or replace it. Rotational fluctuations are • High-pressure oil is leaking from the drain • Replace the abnormally worn part, if any. port, because the motor’s sliding part is worn large out • Replace the abnormally worn part, if any. • Bearing is worn out Oil leak • Oil leak due to breakage of oil seal and O- • Replace the oil seal and O-ring. ring • Oil seal is broken by the internal pressure • Repair the motor and replace the oil generated in the motor case due to the abseal. normal wear of the sliding part of the motor • Pressure increase in the drain piping caused • Clean the clogging in the drain piping and by the clogging of foreign matter resulted in replace the oil seal. breakage of oil seal
2nd speed control Symptoms Major causes Straight-ahead traveling level Spool cannot be switched is low, switching to 2nd speed • Foreign matter is caught travel is disabled • Spring is missing • Spring is damaged • Oil leak due to the abnormal wear of the 2nd speed control piston • 2nd speed control piston is missing • Ball is abnormally worn out
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Remedies • Remove foreign matter and correct or replace the faulty part(s). • Install the spring. • Replace the spring. • Replace the 2nd speed control piston. • Install the 2nd speed control piston. • Replace the ball.
