Hydraulic System
8.222
Model 644E-42/944E-42
Rev. 6/04
c. Extend/Retract 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 extend/retract cylinder (1) 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 tube (2).
2. Secure the extend/retract cylinder in a soft-jawed
vise or other acceptable holding equipment if
possible.
3. Slowly remove the counterbalance valve (3) and the
pilot-operated check valve (4).
IMPORTANT: DO NOT tamper with or attempt to reset
the counterbalance valve cartridge. If adjustment or
replacement is necessary, replace a counterbalance
valve with a new part.
4. Extend the rod (5) as required to allow access to the
base of the cylinder.
IMPORTANT: Protect the finish on the rod at all times.
Damage to the surface of the rod can cause seal failure.
5. Using a pin spanner wrench, unscrew the head
gland (6) from the tube (2). The head gland was
originally torqued to 300-400 lb-ft (407-542 Nm), so
a considerable amount of force is required. Carefully
slide the head gland down along the rod toward the
trunnion end, away from the cylinder tube (2).
IMPORTANT: When sliding the rod and piston assembly
in the tube, prevent the threaded end of the tube from
damaging the piston (7). Keep the rod centered within
the tube to help prevent binding.
6. Carefully pull the rod (5) with all attachments straight
out of the tube (2).
MU3690
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
End of Cylinder
Rod Rotated 180°
For Clarity
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.
Summary of Contents for 944E-42
Page 1: ......
Page 2: ......
Page 14: ...Safety Practices 1 8 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 102: ...Boom 3 56 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 139: ...4 37 Model 644E 42 944E 42 Rev 6 04 Cab and Covers This Page Intentionally Left Blank...
Page 144: ...Cab and Covers 4 42 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 265: ...8 15 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 269: ...8 19 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 273: ...8 23 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 277: ...8 27 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 281: ...8 31 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 285: ...8 35 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 289: ...8 39 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 293: ...8 43 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 297: ...8 47 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 301: ...8 51 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 407: ...8 157 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 425: ...8 175 Model 644E 42 944E 42 Rev 6 04 Hydraulic System This Page Intentionally Left Blank...
Page 501: ...8 251 Model 644E 42 944E 42 Rev 6 04 Hydraulic System MT1950 2 3 4 5 6 7 8 5 5...
Page 507: ...8 257 Model 644E 42 944E 42 Rev 6 04 Hydraulic System MT1950 1 2 3 4 5 6 7 4 4...
Page 508: ...Hydraulic System 8 258 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 525: ...9 17 Model 644E 42 944E 42 Rev 6 04 Electrical System This Page Intentionally Left Blank...
Page 554: ...Electrical System 9 46 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 759: ...10 3 Model 644E 42 944E 42 Rev 6 04 Stabil TRAK System This Page Intentionally Left Blank...
Page 765: ...10 9 Model 644E 42 944E 42 Rev 6 04 Stabil TRAK System This Page Intentionally Left Blank...
Page 785: ...10 29 Model 644E 42 944E 42 Rev 6 04 Stabil TRAK System This Page Intentionally Left Blank...
Page 800: ...Stabil TRAK System 10 44 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 832: ...Transfer Carriage 11 32 Model 644E 42 944E 42 Rev 6 04 This Page Intentionally Left Blank...
Page 840: ...12 8 Model 644E 42 944E 42 Rev 6 04 Index...
Page 841: ...Accident Prevention Tags OS2180 8990403 Origin 5 00 Accident Prevention Tags...
Page 842: ...Accident Prevention Tags OS2180 8990403 Origin 5 00...
Page 843: ......
Page 844: ......