jcb JS 200 Series, Service Manual

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5 - 2
Section F
Transmission
9803/6400
Section F
5 - 2
Issue 2*
Motor/Gearbox
Fault Finding (continued)
Fault Possible cause Countermeasure or remedy
4. Oil Leaks (continued) 2. Motor case excessively pressurised Repair the motor and
resulting in oil leakage. replace oil seal. When inserting new
Oil seal pressure resistance oil seal, be careful not to damage the lip.
Ordinary 0.2 MPa {2 kgf/cm
2
}
Maximum 0.5 MPa {5 kgf/cm
2
}
3. Due to clogging, etc. by foreign matter in Clean the clogged drain piping.
drain pipe, pressure rises causing the There should not be more than 0.3 MPa {3 kgf/cm
2
}
oil seal to leak. pressure on the oil seal. Renew oil seal.
When inserting new oil seal, be
careful not to damage the lip.
Oil seal pressure resistance
Ordinary 0.2 MPa {2 kgf/cm
2
}
Maximum 0.5 MPa {5 kgf/cm
2
}
5. Abnormal noise, 1. When the motor works as a pump, when Recheck the hydraulic circuit and
excessive revolution the closed circuit is used, when the boost repair or replace the double
variation and pressure is low (standard: 0.4~0.5 MPa counterbalance valve.
pressure variation {4~5 kgf/cm
2
}) or when the double Disassemble the motor and replace any
due to cavitation. counterbalance valve operates abnormally worn or broken parts. After
incorrectly, negative pressure is cleaning all parts, reassemble them.
generated on the suction side of the
motor, resulting in cavitation.
Parking Brake
Fault Possible cause Countermeasure or remedy
1. Oil Leaks 1. Disk is worn. Replace the disk. Completely remove
foreign matter and repair damaged areas.
After cleaning, reassemble.
2. Disk surface has changed in quality Grind and recondition the affected area.
or the contact is incorrect. Reassemble after cleaning and replace if
change in quality of the surface is
excessive.
3. Spring is deformed or damaged. Replace the spring. Completely remove
foreign matter and reassemble after
cleaning.
2. Abnormal heat 1. Brake release incorrect. Replace the broken 'O'-ring. Reassemble
generated from 1) Oil leaks due to broken 'O'-ring. after cleaning.
brake drag. 2) Orifice is clogged.
*
*