JLG 500RTS ANSI Service Manual - Manual (Page 32)

SECTION 2 - PROCEDURES
2-16 – JLG Sizzor – 3121103
3. Start the engine and place engine speed and drive
speed control switches to their respective low posi-
tions.
4. Depress the enable switch and activate drive con-
troller to forward position.
5. Using a suitable lifting equipment lift front of
machine up and place an 8 in (20 cm) high block
under left front wheel.
6. With the drive controller activated and engine at idle,
crack open both fittings at lockout cylinder, one at a
time, and close when all air is dissipated (bled).
7. Using a suitable lifting equipment lift front of
machine and remove the 8 in (20 cm) block.
8. Transfer the 8 in (20 cm) high block to right front
wheel and repeat steps 1 through 6, substituting the
word right for left in step 5.
NOTE: After lockout cylinders are bled be sure to engage
drive hubs before removing stop block from rear
wheels.
9. To check lockout cylinder after bleeding, perform the
LOCKOUT CYLINDER CHECK in paragraph 2-19.
2.19 LOCKOUT CYLINDER CHECK
NOTE: Ensure platform is completely lowered prior to begin-
ning lockout cylinder check.
1. Place a 8 in. (20 cm) high block with ascension
ramp in front of left front wheel.
2. Activate machine hydraulic system from platform
control station.
3. Place engine speed and drive speed control
switches to their respective low positions.
4. Place drive controller to forward position and care-
fully drive machine up ascension ramp until left front
wheel is on top of the 8 in (20 cm) high block.
5. Raise machine platform approximately 2 ft (0.6 m);
ensure lockout cylinder cam valve is free of sizzor
arm trip bar.
6. Place drive controller to reverse position and care-
fully drive machine off block and ramp.
7. Have an assistant check to see that left front wheel
remains locked in position off the ground.
8. Lower machine platform; lockout cylinder should
then release the wheel and allow it to rest on the
ground.
9. Transfer the 8 in (20 cm) high block to front of right
front wheel and repeat steps 1 through 8, substitut-
ing the word right for left in steps 1, 4 and 7.
10. If lockout cylinder does not function properly, have
qualified personnel correct the malfunction prior to
any further operation.
2.20 PISTON DRIVE MOTOR - 2WD & 4WD
Disassembly
1. Clean outside of unit thoroughly.
2. Clamp drive shaft in a protected jaw vise with back-
plate end up.
3. Remove six cap screws from backplate.
4. Use a plastic mallet and tap the backplate to loosen
it.
5. Remove o-ring from backplate.
6. Remove complete piston block assembly from
housing assembly.
7. Remove piston assemblies, spider, and pivot from
piston block assembly.
8. The piston block assembly need not be disassem-
bled unless pins or spring are damaged.
THE FOLLOWING PROCEDURE SHOULD BE USED IF THE
SPRING IS TO BE REMOVED FROM THE PISTON BLOCK. THE
S P R I N G I S H I G H LY C O M P R E S S E D A N D T H E S N A P R I N G
SHOULD NOT BE REMOVED WITHOUT COMPRESSING THE
SPRING.