Hydraulic Circuit Operation - Final Positioning Mode, Rod Oil Out - JLG sky trak mmv Service Manual

Stabil-TRAK™ System
11.4.10

Hydraulic Circuit Operation - Final Positioning Mode, Rod Oil Out

FRAME
SWAY
CYLINDER
STABILIZER
CYLINDER
G2
2
5
12B
4B
DE E
.060 DIA.
Pressure
Return
Pilot Pressure
Suction
Load Sense
Conditions:
• Boom angle is above 40°
• Park brake OFF
• Service brake DISENGAGED
• Travel select lever in [F] FORWARD or [R] REVERSE
position
Operation:
Note: Refer to Section 11.4.14, Electrical Schematic - Final
Positioning Mode, for the electrical schematic for this circuit.
As the boom is raised above 40°, the boom proximity
switch is deactivated causing solenoids 12A (1) and
12B (2) to de-energize and solenoids 4A (3) and 4B (4) to
energize. This allows oil to flow from the rod end of the
stabilizer cylinder (5), through solenoid-operated valve
11.14
G3 FTR
9 3
2A
.030 DIA.
10
2B
4A
E
.060 DIA.
4
3
100 PSI
6
7
G1
STABIL-TRAK™
MANIFOLD
8
DE DE-ENERGIZED
E ENERGIZED
PILOT
SELECT
MANIFOLD
TO
JOYSTICK
“T”
V
DE
1
TO
12A
JOYSTICK
“P”
DE
T
P
4B (4), through a .060" orifice (6), through another .060"
orifice (7), then through solenoid-operated valve 4A (3),
then to the base end of the stabilizer cylinder.
The .060" orifices (6 and 7) in solenoid-operated valves
4A (3) and 4B (4) will slow the movement of the rear axle
in reaction to terrain changes. The frame sway will react
normally in this mode.
Because of the greater volume of oil required, extra oil is
required from the system through the 100 psi (7 bar) re-
ducing cartridge (8) in the Stabil-TRAK™ manifold. The re-
strictions produce the slow movement, or FINAL
POSITIONING mode.
HYDRAULIC RESERVOIR
HYDRAULIC
OIL COOLER
PUMP
SECONDARY
FUNCTION
MANIFOLD
CF PIL
T
P
PBG
PP PPG PB
UNLOADER
VALVE
MAIN
CONTROL
VALVE
Model MMV Rev. 12/04
ACCUMULATOR
CHARGE
VALVE
EF ACF ACR LS
LSG
P P1 SW DRAIN
MM2291