Lull 944E-42 Service Manual - Manual (Page 146)

Hydraulic System
8-30 944E-42
8.7.12 Steer Select Valve
The machine can be used in the front-wheel, four-wheel
or crab steering mode. The steer select valve (2) controls
the direction of hydraulic fluid flow to the steering
cylinders mounted on each axle. The steer select valve is
located inside the front dash on the upper left side.
Note: The steer select valve is not serviceable and must
be replaced if defective.
a. Steer Select Manifold and Valve Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, raise the boom, place
the transmission control lever in (N) NEUTRAL,
engage the park brake and shut the engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and the steering wheel, stating that the
machine should not be operated.
3. Open the engine cover. Allow the system fluids to
cool.
4. Properly disconnect the batteries.
5. Remove the front (3) and lower dash panels (4).
6. Label, disconnect and cap the hydraulic hoses
connected to the steering select valve.
7. Remove the retaining nut and remove the steer
selector knob
8. Remove the four socket-head screws that secure the
select valve to the dash
9. Remove the left front dash panel and pull the select
valve through the dash opening. Label and remove
the remaining hoses from the rear of the select
valve.
10. Remove the steer select valve from the cab. Wipe up
any hydraulic fluid spillage in, on, near and around
the machine.
b. Steer Select Valve and Manifold Installation
Note: ALWAYS replace seals, o-rings, gaskets, etc.,
with new parts to help ensure proper sealing and
operation. Lubricate seals and o-rings with clean
hydraulic oil.
1. Place the steer select assembly on a suitable work
surface.
2. Transfer the fittings to the new steer select valve.
Note the orientation of each fitting before removing
them.
3. Place the steer select valve (5) in the front dash
opening and connect all the hoses, except for the
drain hose to their corresponding fittings.
4. Insert the selector valve through the dash and
secure in place with the four capscrews (6).
OU0362
2
3
4
MU4061
6
5