Lull 944E-42 Service Manual - Manual (Page 326)

Hydraulic System
8.74 Model 644E-42/944E-42 Rev. 6/04
8.8.10 Boom Extend Circuit & Troubleshooting (Dual Joystick)
(Refer to Section 8.8.51, “Boom Extend/Retract Circuit Description (Dual Joystick),” for a more detailed
explanation of this circuit.)
Suction
Return
Load Sense
Pressure
Pilot Pressure
PUMP
HYDRAULIC
RESERVOIR
ACCUMULATOR
CHARGE/SECONDARY
FUNCTION VALVE
LS
DRAIN P1
LSG ACR
SW P
ACF EF CF PIL PB
PBG
PPG
SW
MAIN
CONTROL
VALVE
INLET
OUTLET
HYDRAULIC OIL
COOLER
REAR JOYSTICK
3
4
T
P
1 2
CHECK VALVE
85 PSI (5,9 bar)
R E
EXTEND/RETRACT
CYLINDER
RETURN
FILTER
25 PSI
(1,7 BAR)
BYPASS
CHECK
VALVE
ATTACH
TILT
FRAME
EXT/RET LFT/LWR
AU
X
TRANS
MU0551
Pressure
Reducing
Cartridge
Relief
Valve
Main Relief
Valve
“PPG”
Pressure
Tap
Implement
Pump Pressure
Tap
Unloader
Cartridge
Pilot
Supply
Line