SkyTrak 6036 Service Manual - Manual (Page 264)

Stabil-TRAK™ System and Boom Interlock System
10-36 6036, 6042, 8042, 10042, 10054
10.11.10 Hydraulic Circuit Operation -
LOCKED MODE
a. Conditions:
• Boom angle is above 40°
• Park brake ON, or service brake ENGAGED, or
travel select lever in (N) NEUTRAL
b. Operation:
When the conditions are met, solenoids 4A, 4B, 12A
and 12B are de-energized and solenoid 3 is energized.
In the LOCKED MODE, oil is prevented from flowing
through the Stabil-TRAK™
manifold due to check valves
in solenoid-operated valves 4A (1), 4B (2), 12A (3),
and 12B (4).
10.11.11 Hydraulic Circuit Operation -
LOCKED MODE, Frame Level Right
When joystick control is placed in frame level mode,
cables activate the frame level valve in the main control
valve assembly. As the joystick is moved to the right, the
frame level spool valve is shifted, allowing oil to flow
through the valve, to the Stabil-TRAK™
manifold, port V.
Oil entering the Stabil-TRAK™ manifold at port V flows
through solenoid cartridge valve 3 (5), through a 0.030 inch
orifice (6) and check valve 2A (7), to the base end of the
Stabil-TRAK™
cylinder (8). The orifice slows the
movement of the frame level.
Some of this oil is diverted to the pilot line of check valve
2B (9), opening the valve.
Rod end oil from the Stabil-TRAK™ cylinder flows
through check valve 2B (9), opened by pilot pressure in
the Stabil-TRAK™
manifold. The oil then flows through
cartridge valve 3 (5), out of the Stabil-TRAK™ manifold at
port FTR, through a check valve (10), to the rod end of the
frame level cylinder (11).
Oil from the base end of the frame level cylinder flows
through a piloted-open check valve (12) and back
through the frame level spool valve in the frame level
section of the main control valve, dumping the returned
oil to the reservoir.
Pressurized oil entering Stabil-TRAK™ manifold at port P
is stopped at the four closed solenoid-operated valves 4A
(1), 4B (2), 12A (3) and 12B (4). At this time pilot pressure
will cause the 100 psi relief valve (13) to change position,
allowing the excess oil to vent to the reservoir.