Steering Cylinders - JLG sky trak mmv Service Manual

f. Stabilizer Cylinder Installation
1. Lubricate the cylinder pins with multi-purpose
lithium-based grease.
2. Use a sling and hoist or other suitable lifting device
to help install the cylinder. Orient the cylinder with
the cylinder eyelet on top and the rod eyelet on the
bottom.
3. Install the upper cylinder pin. Drive the lubricated
cylinder pin through the cylinder eyelet, frame mount
and self-aligning bearing. Secure the pin with a
capscrew and hex locknut. Torque to 18 lb/ft (24 Nm).
4. Use new flat-faced oiled o-rings when installing the
upper and lower hydraulic hoses. Install and tighten
the hoses onto the appropriate fittings on the
manifold.
WARNING:
operation in closed areas with inadequate ven-
tilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
5. Connect all the wire harness connectors to the
proper solenoids and snap into place.
6. With the help of an assistant, start the engine.
Carefully and slowly, operate the joystick frame sway
function to properly align the rod with the anchor
plate as required. Turn the engine OFF.
7. Install the lower cylinder pin. Drive the lubricated
cylinder pin through the rod eyelet, anchor plate and
self-aligning bearing. Secure the pin with a capscrew
and hex locknut. Torque to 18 lb/ft (24 Nm).
8. Remove all tools, etc. from the vehicle. Carefully
remove the blocking supporting the vehicle frame at
the front and rear axles.
9. Start the engine and run at approximately one-third
to one-half throttle for about one minute without
moving the vehicle or operating any hydraulic
functions. Operate the joystick to fully sway the
frame left and right at least five times each.
WARNING:
under pressure can penetrate the skin, causing
death or serious injury.
10. Inspect for leaks and check the level of the hydraulic
fluid in the reservoir. Shut the engine OFF. Add
hydraulic fluid to the reservoir as required.
11. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
Model MMV Rev. 12/04
Avoid prolonged engine
Escaping hydraulic fluid
g. Stabilizer Cylinder Pressure Checking and
Circuit Bleeding
1. Attach a 5000 psi (345 bar) gauge to the main
control valve at the extend/retract base port relief to
test the frame sway/stabilizer cylinder hydraulic
system circuit pressure. The unit is equipped with
test fittings from the factory. Pressure readings
should be 3500 psi ±100 psi (241,3 ±7 bar). Refer to
Section 9.7, Hydraulic System Testing .
2. Level the frame.
3. Sway the vehicle fully left. Hold the joystick at full
sway left for several seconds, then sway the vehicle
fully right and hold the joystick at full sway right for
several seconds. Observe the readings on the gauge
during the frame sway operations.
4. Level the frame. While leveling the frame, check the
pressure reading on the gauge.
5. Repeat Steps 3-4 five times.
9.14.10

Steering Cylinders

The steering cylinders (25 and 26) are secured to the axle
assemblies. Steer cylinders are covered in the appropri-
ate manufacturer's axle literature. For the front steering
cylinder (25), refer to the ZF Axle Repair Manual, Model
MS-T 3060 (ZF part number 5871 560 002, JLG part #
8990430). For the rear steering cylinder (26), refer to the
ZF Axle Repair Manual, Model MS-T 3045 (ZF part number
5871 550 002, JLG part # 8990419).
26
25
Hydraulic System
Front
MM3840
9.169