SkyTrak 8042 Service Manual - Manual (Page 828)

9.237 Model 8042, 10042, 10054 Legacy Rev. 10/03
Electrical System
9.14.10 Steer Select Valve
The steer select valve (6), is secured to the steer select
manifold and frame with four capscrews and o-rings (7)
on the inside wall of the vehicle frame.
The steer select valve contains two solenoids that direct
hydraulic fluid through hoses and ultimately help operate
the steering. The valve is a direct dual-solenoid operated,
spool-type directional control valve. The steer select
valve controls the start, stop and direction of hydraulic
fluid flow to the steering cylinders mounted on each axle.
The valve consists of a housing (8), two solenoids (9), a
control spool (10) and two return springs (11).
In the de-energized state, the spool (10) is held by the
return springs (11) in the center position. The spool is
shifted through the action of the two wet-pin type
solenoids (9).
The force of an acting solenoid works against the push
pin (12) on the end of the spool (10). The spool is shifted
from its normal position to the end position for the
selected flow. The selected flow pattern is covered in
Section 8, “Hydraulic System.”
When the solenoid is de-energized, the control spool (10)
is returned to its normal (centered) condition by the
centering springs (11).
Check the steer select valve solenoids (13 and 14) for
proper operation, and check the wiring for continuity or
shorts. When energized/de-energized, the solenoid
should move and/or an audible “click” should be heard;
check for the presence of voltage with a voltmeter.
Replace a defective or faulty steer select valve with a new
unit. (Refer to Section 9.7.39, “Front Steer Circuit and
Troubleshooting.”)
MA8320
6
MA8370
7
8 9
10
11
12
9
11
12
MA8310
6
13
14