Hyundai HL955 Manual page 508

Item
Bucket rollback circuit relief
valve check
Bucket dump circuit relief
valve low pressure check
Pilot control valve float
check
Run engine at low idle.
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.
Description
Position bucket at a 45˚ angle
against an immovable object.
Engage transmission in 3rd speed
forward.
LOOK : Bucket angle must not
change.
Raise front of machine which
bucket at 45˚ angle.
Backdrag with bucket while
observing bucket angle.
LOOK : Bucket must not rollback
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.
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
A : Retraction of boom cylinder
rod
B : Retraction of bucket cylinder
rod
Boom cylinder must drift less than
B
7 mm
Bucket cylinder must drift less
A
★
than 10 mm, 12 mm
6-43
Service action
OK
Check complete.
NOT OK
Replace boom lower
check valve.
OK
Go to next check.
NOT OK
Do loader system and
circuit relief valve test at
page 6-57.
OK
Check complete.
NOT OK
Do pilot control valve
pressure test in group 3.
OK
Check complete.
NOT OK
Go to next check.
★
: HL955TM