Lull 944E-42 Service Manual - Manual (Page 458)

Hydraulic System
8.206 Model 644E-42/944E-42 Rev. 6/04
c. Accumulator Charge/Secondary Function Valve
Installation
1. Reassemble all the fittings and diagnostic test
nipples to the accumulator charge/secondary
function valve. Torque all the fittings as specified in
Section 2.3, “Torques.”
2. Align the accumulator charge/secondary function
valve (1) with the carriage bolts (3) in the mount
holes on the valve plate assembly (2).
3. Secure the accumulator charge/secondary function
valve with two carriage bolts (3) and hex nuts (4).
Torque the two hex nuts to 13-23 lb-ft (17-31 Nm).
4. Use new oiled o-rings as required. Reattach and
secure all hoses and fittings. Torque all the hose
fittings as specified in Section 2.3, “Torques.”
5. Reconnect any wire harness connectors.
6. Check the routing of all hoses for sharp bends or
interference with any rotating members, and install
tie wraps and/or protective conduit as required.
Tighten all hose fittings.
7. Lift the valve plate up and secure in position under
the cab. Refer to Section 8.12.1, “Valve Plate
Assembly,” for proper procedure.
8. 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.
9. Inspect the accumulator charge/secondary function
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.
10. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
d. Accumulator Charge Valve Test
Conduct a pressure check of the accumulator circuit. Re-
fer to Section 8.7, “Hydraulic System Testing.”
8.13 ACCUMULATORS
This section covers the testing and charging of the
accumulator system.
The accumulators (5) are located under the floor of the
cab and are mounted to the valve plate (6). The internal
parts of these accumulators are not serviceable. If the
internal diaphragm is leaking, or the seals on the top or
bottom cap are leaking, the accumulator requires
replacement.
The accumulator pre charge pressure will vary depending
on the ambient temperature that the accumulators were
pre-charged at and the actual operating temperature of
the accumulators. The following table shows how the pre-
charge pressure can be affected by temperature range.
The following table depicts the accumulators pre charged
to 450 psi (3103 kPa), at a baseline temperature of 70° F
(21° C).
WARNING:
Avoid prolonged engine
operation in closed areas with inadequate
ventilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
MU1940
1
2
3
4
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.