Operation Manual
72
Preventive Maintenance
Boom Emergency Lower Down Valve
Both of the lift and extend cylinders are equipped with a
needle valve which allows the cylinder to retract without the
direct assist of the machine’s hydraulic power. This feature is
intended to be used only in the event of total loss of engine or
hydraulic pump failure with an elevated boom.
In any event, the Telehandler should be secured until the
situation has been properly evaluated. Secure the Telehandler
and area by following the procedures below:
1. Clear the area around the Telehandler of all personnel.
2. Place the sift lever in NEUTRAL and engage the parking
brake switch to the ON position.
3. Section off a large area under the boom with tape to
restrict any personnel from entering this potentially
dangerous area.
4. If the load is in a position where it can be removed
safely, completely remove the load from the
carriage and/or attachment. Otherwise leave the
load in place.
5. Remove boom access cover on back of boom.
Figure 95. Boom Access Cover
Figure 96. Extend Cylinder Lower Down Valve
The diagnostic on/off switch circuit signals the system that the
operator is requesting to read any active fault code recorded
in the ECM.
When the ECM receives the signal from the diagnostic
ON/OFF switch, the yellow and red warning lights come on
and start flashing if any active fault code is recorded in the
ECM. If both warning lights remain on and do not flash, there
are no active fault codes present.
NOTE: The equipment must be stationary. If road speed is
detected, the flashing sequence will not occur.
Turn the diagnostic switch OFF when the diagnostic system
is not in use.
NOTE: DO NOT touch the top left valve (inset, below)
6. Locate needle valve on extend cylinder. Loosen nut on
valve, then loosen valve with hex wrench.
Figure 97. Lift Cylinder Lower Down Valve
7. Fully retract boom with control handle in cab.
8. When boom is fully retracted, tighten valve with hex
wrench, then tighten nut to secure valve.
9. Locate needle valves on lift cylinders. Loosen nut on
valve, then loosen valve with hex wrench (lower right
valve as shown in Figure 98). Repeat for both sides.
10. Fully lower boom with control handle in cab.
11. When boom is fully lowered, tighten valve with hex
wrench, then tighten nut to secure valve (repeat for both
sides).
