Lull 944E-42 Service Manual - Manual (Page 134)

Hydraulic System
8-18 944E-42
5. Thoroughly clean the main control valve and
surrounding area, including all hoses and fittings,
before proceeding.
6. Label, disconnect and cap all hydraulic hoses
attached to the main control valve, accumulator
charge/secondary function valve and the pilot select
valve. Place a suitable container to catch hydraulic
fluid drainage from beneath the cab.
7. Remove the step assembly from the side of the cab.
Refer to Section 4.5, “Cab Removal.”
8. Check to make sure the two tethers (1) are
positioned in the two mounting tabs (2) on the front
and rear sides of the cab mount. If not, place the
loop of the tether in the mount before proceeding.
9. Place a floor jack under the outer edge of the sub
plate (3) to hold the sub plate in position while
removing the two cap screws (4) and washers
securing the sub plate to the cab support.
10. Remove the cap screws and slowly lower the sub
plate down until the sub plate is supported by the
two tethers mounted on the cab support.
b. Sub Plate with Valve Plate Removal
Refer to Section 4.5, “Cab Removal,” for sub plate
removal procedure and reassembly procedure.
8.7.2 Main Control Valve
The main control valve assembly (5) consists of various
working sections with their own valve assemblies, each
providing a specific hydraulic function. The section
assemblies are the inlet (6), transfer carriage spool
section (7), auxiliary section (8) and the four spool mono
block section (9).
If service to the main control valve assembly is required,
swing the sub plate, with valve plate assembly, down to
gain access to the valve and fittings. Refer to Section
8.7.1, “Valve Plate Assembly.”
a. Main Control Valve Removal from Valve Plate
Before disassembling the main control valve, remove it
from the valve plate assembly. Label and remove all the
hoses from the fittings. Cap and plug all hose ends and
fittings.
1. Wipe up any hydraulic fluid spillage in, on, near and
around the machine and work area.
2. Secure the main control valve in place on the valve
plate to prevent sudden movement when the
hardware is removed.
WARNING
ALWAYS support the sub plate before loosening or
removing any mounting hardware.
MU3822
1 2
3
4
MU3861
6
8
5
7
9
MU3871
10
10