SkyTrak 6036 Service Manual - Manual (Page 258)

Hydraulic System
8.42 Model 6036 Legacy
8.8.15 Four-Wheel Steering Circuit (Left Turn) and Troubleshooting
(Refer to Section 8.8.26, “Steering Circuit Descriptions” for a more detailed explanation of this circuit.)
Figure 8-18 Four-Wheel Steering Hydraulic Circuit (Left Turn)
RETURN
FILTER
FRONT AXLE
SHUTTLE IN TO
MAIN CONTROL
VALVE
SHUTTLE
VALVE
POWER
STEERING
UNIT
R
T
P
L
OPERATOR'S CAB
STEER SELECT
VALVE
SECONDARY
FUNCTION
MANIFOLD
UNLOADER VALVE
DIFFERENTIAL
PRESSURE
SENSE VALVE
PUMP
HYDRAULIC RESERVOIR
PPG PP
T
PBG
P
PS
PSG
PB
VG
SFV
V
P
T
LS
LSG
FRAM
E
EX
T/
RET
LFT/
LW
AUX
LS
a b
A B
P T
Pressure
Suction
Return
Load Sense
DE
SOLENOID COIL
STATE
ENERGIZED
DE-ENERGIZED
E
DE
HYDRAULIC
OIL COOLER
E
REAR AXLE
POWER
STEERING
PRESSURE
REDUCING
VALVE
IN T
T
ATTACH
TI
LT
MA6790
NOTE:
When checking pressures
in circuits, refer to Section
8.7, “Hydraulic System
Testing” for correct
pressure readings.
Before troubleshooting
any hydraulic circuit,
ALWAYS begin by
checking the
following:
1. Hydraulic oil level in
the reservoir
2. All hoses, tubes,
fittings for leaks,
kinks, interference,
etc.
3. Air in the lines
Not
OK
Not
OK
If the steering is slow or difficult,
check the pressure at the “PSG” port
of the secondary function manifold.
If OK
Check packing in steering cylinders.
If OK
Repair/replace cylinder(s).
Not
OK
Not
OK
Check the power steering unit. Replace power steering unit.
Check the shuttle valve. Replace shuttle valve.
If OK
If OK
Adjust/repair/replace pressure-reducing
valve on secondary function manifold.
Not
OK
Verify that the check valve fitting at the
power steering unit is operating properly.
Replace check valve fitting.