6-43
Item
Description
Service action
Bucket rollback circuit relief
valve check
Position bucket at a 45˚ angle
against an immovable object.
Engage transmission in 3rd speed
forward.
LOOK : Bucket angle must not
change.
OK
Check complete.
NOT OK
R e p l a c e b o o m l owe r
check valve.
Bucket dump circuit relief
valve low pressure check
Raise front of machine which
bucket at 45˚ angle.
Backdrag with bucket while
observing bucket angle.
LOOK : Bucket must not rollback
OK
Go to next check.
NOT OK
Do loader system and
circuit relief valve test at
page 6-57.
Pilot control valve float
check
Run engine at low idle.
With the bucket partially dumped,
lower boom to raise front of
machine.
Push control lever to the float
detent position and release lever.
LOOK : Front of machine lower to
the ground and valve must remain
in float position when lever is
released.
OK
Check complete.
NOT OK
Do pilot control valve
pressure test in group 3.
B o o m c y l i n d e r a n d
b u c k e t c y l i n d e r d r i f t
check
H e a t hy d r a u l i c o i l t o
operating temperature.
S e t t h e b o o m a n d b u c k e t
horizontal, then stop the engine.
Stop the engine, wait for 5
minutes, then start measuring.
Measure the amount the lift and
dump cylinder rods retract during
15 minutes. (unloaded bucket)
A : Retraction of boom cylinder
rod
B : Retraction of bucket cylinder
rod
Boom cylinder must drift less than
7 mm
Bucket cylinder must drift less
than 10 mm,
★
12 mm
OK
Check complete.
NOT OK
Go to next check.
★
: HL955TM
B
A
A
B
Summary of Contents for HL955
Page 557: ...7 6 MEMORANDUM MEMORANDUM ...
