Lull 944E-42 Service Manual - Manual (Page 129)

8-13 944E-42
Hydraulic System
8.5 HYDRAULIC RESERVOIR
The hydraulic reservoir (1) is located on the right side of
the machine. The reservoir is held in place inside the
engine pod.
Occasionally, fluid may seep, leak or be more forcefully
expelled from the filter head (2) when system pressure
exceeds the rating of the filter head or breather. If the
return filter becomes plugged, return hydraulic oil will
bypass the filter when pressure reaches 25 psi (1,7 bar)
and return to the reservoir unfiltered.
Carefully examine fluid seepage or leaks from the
hydraulic reservoir to determine the exact cause. Clean
the reservoir and note where any seepage occurs.
Leaks from a cracked or damaged reservoir require that
the reservoir be removed from the machine, flushed
completely with water and repaired by a certified welder
using approved techniques. If these conditions cannot be
met, the reservoir must be replaced in its entirety.
8.5.1 Hydraulic Oil Reservoir Draining
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower 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. Open the filler cap on the hydraulic oil reservoir.
Remove the drain plug on the side of the hydraulic
oil reservoir.
6. Transfer the used hydraulic oil into a suitable
covered container, and label as "Used Oil". Dispose
of used oil at an approved recycling facility. Clean
and reinstall the drain plug.
7. Wipe up any hydraulic fluid spillage in, on, near and
around the machine and the work area.
8.5.2 Hydraulic Oil Reservoir Filling
1. Be sure the reservoir is clean and free of all debris.
2. Install a new hydraulic oil filter.
3. Fill the reservoir with Mobilfluid 424 ® (ISO Grade 46)
oil. Refer to Section 2.4, “Fluid and Lubricant
Capacities.”
4. Properly connect the batteries.
5. Close and secure the engine cover.
8.5.3 Hydraulic Oil Reservoir Replacement
a. Hydraulic Oil Reservoir Removal
1. Park the machine on a firm, level surface, level the
machine, fully retract the boom, lower 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. Remove all of the hydraulic oil from the reservoir and
system. The receptacle must be large enough to
hold 50 gallons of oil. Remove the drain plug (1) and
allow the oil to drain into the receptacle. Dispose of
used oil at an approved recycling facility.
Note: If an oil evacuation system is available, removal
of the hydraulic oil can best be accomplished by
evacuating the oil through the filler tube.
MU7440
1
2
FRONT
MU7390
1
3
2