jcb JS300 Service Manual page 923

Boom Ram Speed
1 Position the dig end as shown.
Fig 10.
2 Measure the time it takes the boom ram to open from
the closed position.
3 Repeat five times and calculate the average time.
4 Measure the time it takes the boom ram to close from
the open position.
5 Repeat five times and calculate the average time.
Note: Place a wooden block where the dipper would make
contact with the ground, so as to prevent a shock loading
of the dipper, when it is lowered.
E-262
Hydraulic System Fault Finding
Swing Speed
1 Position the dig end in the minimum Swing position
facing forwards.
2 Rotate the upper framework and after one complete
rotation measure the time it takes for the next
rotations.
Travel Speed
1 Raise one track off the ground by Swinging the
machine through 90 degrees and lifting the machine
using the boom and dipper.
2 Make a mark on the outside edge of the track
gearbox.
A357573-C2
3 Operate the track motor in forward and reverse for 5
minutes, changing gear at regular intervals to
distribute warm oil through the system.
4 Record the time it takes for the motor to complete the
applicable number of revolutions as follows:
Creep speed - 10 revs.
Slow speed - 20 revs.
Fast speed - 30 revs.
9813/5100-1
Section E - Hydraulics
Test 008: Testing Machine Cycle Times
5
E-262