Hydraulic troubleshooting - extend interlock mode – SkyTrak 8042 Service Manual User Manual
Page 893
Stabil-TRAK™ System and Boom Interlock System
10.52
Model 8042, 10042, 10054 Legacy
Rev. 10/03
10.13.2
Hydraulic Circuit Operation -
Extend Interlock Mode
Operation:
When the outriggers in the RAISED position, the
outrigger pressure switches (1 and 2) are open.
As the boom is extended past the boom extend switch,
the switch opens, de-energizing the boom lockout
solenoid (3). This allows pressurized oil to flow through
the valve body (4) to the piston side of the pilot-operated
valve (5), causing it to close. This prevents oil flow to the
extend/retract cylinder (6), preventing the boom from
being extended further.
The retract function is still allowed, as oil flow through the
boom lockout valve reversed, forcing the pilot-operated
check valve (7) and counterbalance valve (8) to open.The
oil flow will cause the pilot-operated valve (5) to open,
returning oil to the main control valve (9) and
reservoir (10).
10.13.3
Hydraulic Troubleshooting - Extend Interlock Mode
Not
OK
Not
OK
Not
OK
When engaging the boom extend
controls, the boom does not extend.
Conditions:
• Ignition ON, engine
running
• Outriggers RAISED
• Travel select lever in
(F) FORWARD or
(R) REVERSE
• Park brake OFF
• Service brake
DISENGAGED
Check solenoid coil from the boom
lockout valve for correct resistance
(7-9 ohms).
Remove solenoid cartridge from boom
lockout valve and inspect
for debris or damage. Refer to Section
8.12.9, “Extend Lockout Valve (10054).”
Replace solenoid.
Clean passages or replace cartridge.
If OK
If OK
If OK
Not
OK
Replace check valve(s).
Inspect check valves on extend/retract
cylinder. Refer to Section 8.13.6,
Check electrical wiring.
Refer to Section 10.9, “Stabil-TRAK™
Boom Interlock Electrical Circuit
(10054, 13198-17984),” or Section
10.10, “Stabil-TRAK™ Boom Interlock
Electrical Circuit Operation and