Service Manual User guide

8.1
Model 644E-42/944E-42 Rev. 6/04
Section 8
Hydraulic System
Contents
PARAGRAPH TITLE PAGE
8.1 Hydraulic Component Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5
8.2 Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6
8.3 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7
8.4 Hydraulic Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7
8.5 Hoses, Tube Lines, Fittings, Etc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8
8.5.1 Replacement Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8
8.5.2 Hose, Tube, Line and Fitting Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8
8.5.3 Snap Lock Fittings & Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8
8.6 Hydraulic Pressure Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.10
8.6.1 Pressure Checks and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8.11
8.7 Hydraulic System Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12
8.7.1 Hydraulic Testing (SN 18460 and Before, Dual Joystick, 644E Only) . . . . . . . . . . . . . . . . . . . . 8.12
8.7.2 Hydraulic Testing (SN 18461 thru 18927, Dual Joystick, 644E Only) . . . . . . . . . . . . . . . . . . . . 8.16
8.7.3 Hydraulic Testing
(SN 18928 thru 20118, 0160002519 thru 0160003087, Dual Joystick, 644E Only) . . . . . . . 8.20
8.7.4 Hydraulic Testing (SN 0160003088 and After, Dual Joystick, 644E Only). . . . . . . . . . . . . . . . . 8.24
8.7.5 Hydraulic Testing
(SN 18928 thru 20118, 0160002519 thru 0160003087 Single Joystick, 644E Only) . . . . . . . . 8.28
8.7.6 Hydraulic Testing (SN 0160003088 and After Single Joystick, 644E Only). . . . . . . . . . . . . . . . 8.32
8.7.7 Hydraulic Testing (SN 18927 and Before, Dual Joystick, 944E Only) . . . . . . . . . . . . . . . . . . . . 8.36
8.7.8 Hydraulic Testing
(SN 18928 thru 20123, 0160002514 thru 0160003085, Dual Joystick, 944E Only) . . . . . . . 8.40
8.7.9 Hydraulic Testing (SN 0160003086 and After, Dual Joystick, 944E Only). . . . . . . . . . . . . . . . . 8.44
8.7.10 Hydraulic Testing
(SN 18928 thru 20123, 0160002514 thru 0160003085, Single Joystick, 944E Only) . . . . . . . . 8.48
8.7.11 Hydraulic Testing (SN 0160003086 and After Single Joystick, 944E Only). . . . . . . . . . . . . . . . 8.52
8.8 Hydraulic Circuits and Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.55
8.8.1 Pump & Cooling Circuit & Troubleshooting (Dual Joystick, SN 18460 and Before). . . . . . . . . . 8.56
8.8.2 Pump & Cooling Circuit & Troubleshooting (Dual Joystick, SN 18461 and After) . . . . . . . . . . . 8.58
8.8.3 Pump & Cooling Circuit & Troubleshooting (Single Joystick). . . . . . . . . . . . . . . . . . . . . . . . . . . 8.60
8.8.4 Joystick Circuit & Troubleshooting (Front - Dual Joystick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.62
8.8.5 Joystick Circuit & Troubleshooting (Rear - Dual Joystick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.64
8.8.6 Joystick Circuit & Troubleshooting (Single Joystick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.66
8.8.7 Park Brake Circuit & Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.68
8.8.8 Service Brake Circuit & Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.70
8.8.9 Emergency Towing Park Brake Release Circuit & Troubleshooting. . . . . . . . . . . . . . . . . . . . . . 8.72
8.8.10 Boom Extend Circuit & Troubleshooting (Dual Joystick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.74
8.8.11 Boom Extend Circuit & Troubleshooting (Single Joystick) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.76