Lull 944E-42 Service Manual - Manual (Page 261)

8.9 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
a. Disconnection Procedure
1. Relieve the hydraulic pressure in the appropriate
circuit before attempting to disconnect any of these
snap lock fittings. Refer to Section 8.2, “Safety
Information,” “To Relieve Hydraulic Pressure.” To
relieve the pressure, slowly loosen the appropriate
bleed plug (4) on the top of the block (5) directly
inline with the circuit being disconnected. Tighten
the bleed plug after the pressure has been released.
Torque the plugs to 14-16 lb-ft (19-22 Nm).
2. Clean the area around the snap lock fittings prior to
disconnection.
3. To help prevent damage to the release sleeve (6),
create a release tool insertion gap (7) by moving the
sleeve in the release direction. This can be done by
hand or by using a single prong on the release tool.
4. Insert the release tool behind the release sleeve and
pull the hose assembly out from the mating
connector. DO NOT pry on the fitting with the
release tool.
5. If a release tool is not available, a thin blade
screwdriver may be used to release the lockring (8).
Care must be used to avoid damage to the release
sleeve.
b. Inspection
These fittings are designed to be connected and
disconnected repeatedly without replacing the o-ring (9)
or back-up ring (10) unless leakage or damage is
observed.
1. Inspect both the male (11) and female (12)
connectors to ensure they are in good condition, free
of nicks, scratches and contamination. If damage is
observed the fittings need to be replaced.
2. If the o-ring (9) or back-up ring (10) are damaged
they can be replaced. Refer to the parts manual for
ordering the appropriate kit.
3. Check the wire lockring (8) to be sure it is in the
proper position in the female connector, prior to
installation or reconnection of the fittings.
c. Connection Procedure
1. Align the fitting on the hose with the mating
connector. Push the fitting straight into the mating
connector until you feel a definite snap and you feel
a solid stop.
2. Pull back on the hose assembly to verify that a
proper connection has been made and the two
fittings are securely locked together.
3. Clear the area around the roll back hoses of all
personnel.
4. After all hose connections are complete, start the
engine and SLOWLY function the boom cylinders
(lift/lower, extend/retract and attachment tilt) and the
auxiliary hydraulic to verify that a good snap lock
connection has been made.
WARNING:
Relieve hydraulic pressure
before servicing any hydraulic component.
Escaping hydraulic fluid under pressure can
penetrate the skin causing death or serious
injury.
4
5
MU0430
WARNING:
Before checking hose
connections, clear the area of all personnel.
Escaping hydraulic fluid under pressure can
penetrate the skin causing death or serious
injury.
MU0440
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8
9
10
11
12