8.69
Model 644E-42/944E-42
Rev. 6/04
Hydraulic System
Not
OK
Not
OK
Not
OK
If park brake fails to hold, check
the “PBG” port on the
accumulator charge/secondary
function valve. Should read 0 psi.
If park brake fails to release,
check the “PBG” port on the
accumulator charge/secondary
function valve. Should read
500-600 psi (34,5-41,4 bar).
Check pressure reducing
cartridge on accumulator charge/
secondary function valve.
Refer to Section 9.14.6,
Not
OK
Within the front axle:
If not holding, check the park
brake springs.
If not releasing, check the
piston seals.
Refer to ZF Axle Repair
Manual, Model MS-T 3045,
ZF part # 5871 550 002. JLG
part # 8990419 (644E Only)
or ZF Axle Repair Manual,
Model MS-T 3060, ZF part #
5871 560 002. JLG part #
8990430 (944E Only)
Install seal kit/replace
solenoid valve cartridge.
If OK
Adjust/repair/replace
pressure reducing cartridge.
If OK
Check solenoid valve
cartridge.
Check solenoid valve on the
accumulator charge/
secondary function valve.
If OK
NOTE:
When checking pressures in
circuits, refer to Section 8.7,
“Hydraulic System Testing,” for
correct pressure readings.
Not
OK
Check front brake discs for
wear.
Refer to Section 5.6.1, “Brake
If OK
Before troubleshooting any
hydraulic circuit, ALWAYS
begin by checking the
following:
1. Hydraulic oil level in the
reservoir
2. All hoses, tubes, fittings
for leaks, kinks,
interference, etc.
3. Air in the lines
Summary of Contents for 944E-42
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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...
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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...
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