Lull 944E-42 Service Manual - Manual (Page 465)

8.213 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
4. ALWAYS use new oiled o-rings, seals, gaskets, etc.
DO NOT over-stretch seals, wipers and o-rings. After
installing such parts, verify that they are not twisted
in their grooves.
5. To aid in installation, lubricate piston seals and the
seal installation path with clean, filtered hydraulic oil.
6. Lubricate the outer surfaces of the seals and o-rings
and the inside of the tube, piston and head gland
with clean, filtered hydraulic oil. Use a suitable
installation or compression tool when installing the
piston and head gland into the cylinder to help
prevent twisting or damaging the seals and o-rings.
When sliding the rod and piston assembly in the
tube, DO NOT damage the piston by scraping it
against the threads in the tube. Keep the rod in line
with the tube to prevent binding.
7. Follow the manufacturer’s instructions when
applying primer, locking or retaining compounds that
are specified in the cylinder assembly procedures.
The use of primer is recommended in some cases to
decrease cure time. Allow sealant to cure fully before
proceeding with the assembly procedure. The curing
process may be hastened by the use of a heat gun
to blow warm, dry air on the parts.
8. After assembling a cylinder, test the cylinder at low
operating pressures. Verify that the piston and rod
move freely in both directions.
9. Increase the operating pressure to the maximum
pressure recommended for the cylinder. Check for
external leakage and for free movement in both
directions.
10. Retract the piston fully. Cap the hydraulic fittings.
8.14.4 Attachment Tilt Cylinder
The attachment tilt cylinder (9) is attached at the front of
the inner boom inside the gooseneck (10).
a. Attachment Tilt Cylinder Removal
1. Remove any attachment from the vehicle. Park the
vehicle on a firm, level surface, fully retract all
hydraulic cylinders. Allow sufficient work space at
the front of the boom. Raise the boom enough to
allow the quick attach or the bottom of the
gooseneck to clear the ground. Place the travel
select lever in the [N] NEUTRAL DETENT position,
engage the park brake switch and shut the engine
OFF.
2. Place an Accident Prevention Tag on both the
ignition switch and the steering wheel, stating that
the vehicle should not be operated. Refer to Section
1.5, “Accident Prevention Tag Usage.”
3. Unlatch and open the engine cover. Allow the
hydraulic fluid to cool.
4. Label or otherwise mark the hydraulic hoses in
relation to the attachment tilt cylinder. Disconnect
and cap both hoses and attachment tilt cylinder
fittings. Refer to Section 3.6.5, “Attachment Tilt
Cylinder Removal.”
5. Remove the attachment tilt cylinder from the vehicle.
6. Wipe up any hydraulic fluid spillage in, on, near or
around the vehicle.
MU3510
9
10
WARNING:
Hot hydraulic fluid can
cause severe burns. Wait for hydraulic fluid to
cool before servicing any hydraulic component.
WARNING:
Escaping hydraulic fluid
under pressure can penetrate the skin, causing
death or serious injury. Relieve hydraulic
pressure before servicing any hydraulic
component.