6-44
Item
Description
Service action
Boom cylinder leakage
check
H e a t hy d r a u l i c o i l t o
operating temperature.
Dump bucket until teeth or cutting
edge is perpendicular to the
ground.
Raise boom until cutting edge is
about 1 m (3 ft) above ground.
Stop engine. Measure drift from
tooth or cutting edge to ground for
1 minute.
Wait 10 minutes.
Measure drift from tooth or cutting
edge to ground for 1 minute.
LOOK : Compare the drift rate
between the first measurement
and the second measurement.
OK
Drift is approximately the
same between first and
second measurement.
Repair loader control
valve or circuit relief valve.
NOT OK
If drift is considerably less
on second measurement,
repair cylinder.
Bucket cylinder leakage
check
H e a t hy d r a u l i c o i l t o
operating temperature.
Raise bucket about 1 m (3 ft) off
ground with bucket level.
Stop engine. Place a support
under boom.
Measure drift from tooth or cutting
edge to ground for 1 minute.
Wait 10 minutes.
Measure drift from tooth or cutting
edge to ground for 1 minute.
LOOK : Compare the drift rates
between the first measurement
and the second measurement.
OK
Drift is approximately the
same between first and
second measurement.
Repair loader control
valve or circuit relief valve
at page 6-57.
NOT OK
Drift is considerably less
on second measurement.
Repair cylinder.
Check valve of safety
valve leakage check
H e a t hy d r a u l i c o i l t o
operating temperature.
Put bucket level and position
about 1.2 m (4 ft) above ground.
Place a piece of tape on cylinder
rod at least 51 mm (2 in) from rod
guide.
Run engine at low idle in safety-
release position.
LOOK : Bucket must not drift up.
OK
Check complete.
NOT OK
Check or replace safety
valve.
Pilot control valve
(RCV lever) check
Stop engine. Turn key switch to
OFF position.
Move control lever to all positions
and then release.
LOOK : Lever must return to
neutral when released from all
positions.
OK
Check completed.
NOT OK
Repair pilot control valve.
Summary of Contents for HL955
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