Lull 944E-42 Service Manual - Manual (Page 439)

8.187 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
4. Clean all components with a suitable cleaner before
inspection.
5. Inspect internal passageways of the pilot select
valve and its component parts for wear, damage, etc.
If inner surfaces of the pilot select valve DO NOT
display an ultra-smooth, polished finish, or
components are damaged in any way, replace the
pilot select valve or appropriate part. Often, dirty
hydraulic fluid causes failure of internal seals and
damage to the polished surfaces within the pilot
select valve.
6. Secure the pilot select valve block (7) in a bench vise
or by other suitable means.
7. Install the elbow fittings (6) into the “A3” and “B1”
ports on one side of the block (7) and into the “P1”
and “P2” ports on the other side.
8. Install the straight fittings (8) into the “A1” and “B3”
ports on one side of the block.
9. Install the two solenoid cartridges (9) into the block.
Torque the cartridges to 20 lb-ft (27 Nm). Torque the
solenoid nuts to 5 lb-ft (7 Nm).
c. Pilot Select Valve Installation
1. Position the pilot select valve (5) back onto the valve
plate.
2. Insert the two capscrews (4) through the pilot select
valve (5) and secure to the valve plate. Torque the
two capscrews to 5-9 lb-ft (7-12,5 Nm).
3. Reattach and secure all hoses and fittings.
4. Reconnect any wire harness connectors.
5. Start the engine and run at approximately one-third
to one-half throttle for about one minute without
moving the vehicle or operating any hydraulic
functions.
6. Inspect the pilot select valve for leaks and check the
level of the hydraulic fluid in the reservoir. Shut the
engine OFF.
Note: Check for leaks and repair as required before
continuing. Add hydraulic fluid to the reservoir as
needed.
7. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
8. Reinstall the access plate (10) to the cab floor.
Secure in place with the capscrews (11). Torque the
capscrews to 18 lb-ft (25 Nm).
d. Pilot Select Valve Test
Conduct a pressure check of the joystick circuit. Refer to
Section 8.7, “Hydraulic System Testing.”
MU4050
6
7
8
9
6
6
“A1” and “B3”
Ports
“B1”
Port
“A3”
Port
WARNING:
Avoid prolonged engine
operation in closed areas with inadequate
ventilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
WARNING:
Hydraulic oil leaking under
pressure can penetrate the skin and cause
severe personal injury. DO NOT use your hand
or any part of your body to check for hydraulic
leaks. When checking for hydraulic leaks, wear
safety glasses and gloves to help provide
protection from spraying hydraulic oil. Use a
piece of cardboard or paper to search for
leaks.
MU3770
10
11