jcb JS200 Service Manual page 458

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