SkyTrak 8042 Service Manual - Manual (Page 506)

8.91 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
Verify the correct operation of the solenoids before
considering replacement of the secondary function
manifold. Refer to Section 9, “Electrical System.” The
manifold itself is not serviceable and must be replaced if
defective.
Note: DO NOT loosen, disassemble or attempt to adjust
any of the pressure valves unless specifically instructed
by JLG to do so! Tampering with a pressure valve will
irrevocably alter pressure in the affected circuits.
a. Secondary Function Manifold Replacement
1. Park the vehicle on a firm, level surface, fully retract
the boom, raise the boom, place the travel select
lever in (N) NEUTRAL, place the neutral lock lever in
the (N) NEUTRAL LOCK position, engage the park
brake switch and shut the engine OFF.
2. Place an Accident Prevention Tag on both the
ignition key switch and the steering wheel, stating
that the vehicle should not be operated. Refer to
Section 1.5, “Accident Prevention Tags.”
3. Temporarily block up or support the raised boom.
4. Unlock and open the rear door. Allow the hydraulic
fluid to cool.
5. Remove the transmission covers.
6. Label or otherwise mark the hydraulic hoses in
relation to the secondary function manifold.
Disconnect and cap all hoses, fittings, solenoid wire
terminal leads, etc.
7. Remove the two hex flange nuts from the carriage
bolts securing the secondary function manifold to the
frame. Remove the secondary function manifold
from the vehicle. Wipe up any hydraulic fluid spillage
in, on, near and around the vehicle.
MH3750
Front
~
6
WARNING:
DO NOT get under a raised
boom unless the boom is blocked up. Always
block the boom before doing any servicing that
requires the boom to be up. Unexpected lowering
of the boom may cause death or serious injury.
WARNING:
Hot hydraulic fluid can
cause severe burns. Wait for hydraulic fluid to
cool before servicing any hydraulic component.
WARNING:
Escaping hydraulic fluid
under pressure can penetrate the skin, causing
death or serious injury. Relieve hydraulic
pressure before servicing any hydraulic
component.