Lull 944E-42 Service Manual User Manual download pdf (Page 482)

100

101

Hydraulic System

8.230

Model 644E-42/944E-42 Rev. 6/04

g. Lift/Lower Cylinder Pressure Checking and

Circuit Bleeding

1. Attach a 5000 psi (345 bar) gauge to the main

control valve to test the lift/lower cylinder hydraulic

system circuit pressure. The unit is equipped with

test fittings from the factory. Refer to Section 8.7,

“Hydraulic System Testing.”

2. With no accessory installed on the quick attach, start

with the lift/lower and attachment tilt cylinders fully

retracted.

3. Fully raise and fully extend the boom. Hold the joystick

at full extend while fully raising the lift/lower cylinder.

4. Fully retract the attachment tilt cylinder. Hold the

joystick at full retract while fully lowering the boom.

5. Repeat Steps 3 thru 4 five times.

8.14.8 Frame Sway Cylinder

The frame sway cylinder (1) is attached to the right side

of the frame at the front axle and to the cast loop on the

axle.

a. Frame Sway Cylinder Removal

1. Park the vehicle on a firm, level surface, fully retract

all hydraulic cylinders, ground the attachment (if

any), 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 cylinder being removed. Safely

position suitable supports between the frame and

axle to prevent the frame from leaning to one side.

5. Disconnect and cap all hoses and fittings, etc.

6. Use a sling and hoist or other suitable lifting device

to support the cylinder. Remove the nuts,

capscrews, and cylinder mount pins securing the

cylinder to the frame and anchor on the front axle.

7. Remove the cylinder from the vehicle. Wipe up any

hydraulic fluid spillage in, on, near and around the

vehicle.

b. Frame Sway Cylinder Disassembly

Note: An additional o-ring may be included at the base

of the cylinder rod. This additional o-ring may be

discarded, as it served only in a temporarily protective

role.

1. Clean the frame sway cylinder (2) with a suitable

cleaner. Remove all dirt, debris and grease from the

cylinder.

IMPORTANT: Avoid using excess force when clamping

the cylinder in a vise. Apply only enough force to hold the

cylinder securely. Excessive force can damage the

cylinder.

2. Secure the frame sway cylinder (2) in a soft-jawed

vise or other holding device, and place a suitable

container beneath the cylinder to catch hydraulic

fluid run-off.

3. Slowly remove the pilot-operated check valves (3)

from the frame sway cylinder.

WARNING: Hot hydraulic fluid can

cause severe burns. Wait for hydraulic fluid to

cool before servicing any hydraulic component.

MU1110

WARNING: Escaping hydraulic fluid

under pressure can penetrate the skin, causing

death or serious injury. Relieve hydraulic

pressure before servicing any hydraulic

component.

WARNING: Significant pressure may be

trapped inside the cylinder. Exercise caution

when removing a counterbalance valve or a

pilot-operated check valve from a cylinder.

Escaping hydraulic fluid under pressure can

penetrate the skin, causing death or serious

injury.

1 2 ... 477 478 479 480 481 482 483 484 485 486 487 ... 845 846

Comments to this Manuals

No comments

Lull 944E-42 Service Manual User Manual Page 482

Comments to this Manuals

Related products and manuals for Special machinery Lull 944E-42 Service Manual