JLG M600 Service Manual - Manual (Page 69)

SECTION 3 - CHASSIS & TURNTABLE
3121813 – JLG Lift – 3-31
3.6 OSCILLATING AXLE LOCKOUT TEST (IF
EQUIPPED)
LOCKOUT SYSTEM TEST MUST BE PERFORMED QUARTERLY,
ANY TIME A SYSTEM COMPONENT IS REPLACED, OR WHEN
IMPROPER SYSTEM OPERATION IS SUSPECTED.
NOTE: Ensure boom is fully retracted, lowered, and cen-
tered between drive wheels prior to beginning lock-
out cylinder test.
1. Place a 6 inches (15.2 cm) high block with ascen-
sion ramp in front of left front wheel.
2. From platform control station, start engine
3. Place the Drive control lever to the forward position
and carefully drive machine up ascension ramp until
left front wheel is on top of block.
4. Carefully activate Swing control lever and position
boom over right side of machine.
5. With boom over right side of machine, place Drive
control lever to Reverse and drive machine off of
block and ramp.
6. Have an assistant check to see that left front or right
rear wheel remains elevated in position off of
ground.
7. Carefully activate Swing control lever and return
boom to stowed position (centered between drive
wheels). When boom reaches center, stowed posi-
tion, lockout cylinders should release and allow
wheel to rest on ground, it may be necessary to acti-
vate Drive to release cylinders.
8. Place the 6 inches (15.2 cm) high block with ascen-
sion ramp in front of right front wheel.
9. Place Drive control lever to Forward and carefully
drive machine up ascension ramp until right front
wheel is on top of block.
10. With boom over left side of machine, place Drive
control lever to Reverse and drive machine off of
block and ramp.
11. Have an assistant check to see that right front or left
rear wheel remains elevated in position off of
ground.
12. Carefully activate Swing control lever and return
boom to stowed position (centered between drive
wheels). When boom reaches center, stowed posi-
tion, lockout cylinders should release and allow
wheel to rest on ground, it may be necessary acti-
vate Drive to release cylinders.
13. If lockout cylinders do not function properly, have
qualified personnel correct the malfunction prior to
any further operation.
3.7 OSCILLATION CYLINDER BLEEDING
NOTE: The oscillating axle must be checked daily for proper
operation.
Bleeding Procedure
1. Run one side wheel onto a ramp or block of wood.
On the other side, the lockout cylinder should be
extended.
2. Block the rear wheels and disconnect the drive
hubs.
NOTE: Step three is only for models with all wheel drive.
3. Next, unplug the 4 wheel assist valve under the
frame.
4. Have an assistant activate drive forward and tele-
scope in from the platform. Open up the bleeder
screws on the extended side lockout cylinder. Let
the hydraulic oil run out until all the air bubbles are
out of the cylinder. Then close the bleeder screws.
Checking Oscillation Cylinders
After bleeding the lockout cylinders, check to see that
they are holding their position when oscillated.
1. Reconnect the drive hubs and 4-wheel assist valve.
2. Run one wheel onto a ramp or a block of wood,
mark the retracted cylinder with a marker, swing the
turntable off of the cam valve.
3. Back the unit off of the ramp, check the retracted
cylinder for drive no more than ½" (12.7 mm).
4. Repeat this procedure for the other side. If the lock-
out cylinders do not hold, repeat the bleeding proce-
dure or check for the following:
a. Air in lockout system.
b. Bad cylinder seals.
c. Bad holding valves.