Toro groundsmaster 455-D - Chapter 4 Hydraulic System; Chapter 8 - Cutting Unit; General Information

Chapter 4
Hydraulic System
Table of Contents
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 2
TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . 3
Test No. 1: Checking Traction Circuit
Hydraulic Hose and Fitting Information . . . . . . . . 3
Working Pressure or Relief Pressure. . . . . . . 20
HYDRAULIC SCHEMATICS . . . . . . . . . . . . . . . . . . 5
Test No. 2: Checking Counterbalance Pressure 21
Two (2) Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 5
Test No. 3: Checking Wing Deck
Four (4) Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 6
Counterbalance Pressure . . . . . . . . . . . . . . . 22
HYDRAULIC FLOW DIAGRAMS . . . . . . . . . . . . . . . 7
Test No. 4: Checking Steering Circuit
General Auxiliary Pump Flow . . . . . . . . . . . . . . . 7
Working Pressure or Relief Pressure. . . . . . . 23
Traction Circuit - Forward . . . . . . . . . . . . . . . . . . 8
Test No. 5: Checking Lift Circuit
Lift/Lower Circuit - Lifting Cutting Unit . . . . . . . . . 9
Working Pressure or Relief Pressure. . . . . . . 24
Steering Circuit - R.H. Turn . . . . . . . . . . . . . . . . 10
Test No. 6: Checking Charge Pressure
SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
For Traction Circuit. . . . . . . . . . . . . . . . . . . . . 25
Hydraulic Pressure Test Kit . . . . . . . . . . . . . . . . . 11
ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Hydraulic Tester. . . . . . . . . . . . . . . . . . . . . . . . . 12
Traction Pump Neutral Adjustment . . . . . . . . . . 26
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 13
REPAIRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
System Operates Hot . . . . . . . . . . . . . . . . . . . . 13
Removing Hydraulic System Components . . . . 27
Machine Travels in One Direction Only . . . . . . . 13
Traction Pump Shaft Seal Replacement . . . . . . 28
Traction Response is Sluggish . . . . . . . . . . . . . 14
Traction Pump Trunnion Seal Replacement . . . 29
Machine Will Not Travel in Either Direction . . . . 14
Traction Pump Check and
Four Wheel Drive Does Not Engage . . . . . . . . . 15
High Pressure Relief Valves . . . . . . . . . . . . . 30
Four Wheel Drive Does Not Disengage . . . . . . 15
Traction Pump Charge Pressure Relief Valve . . 31
Cutting Unit(s) Do Not Lift or Lift Too Slowly . . . 16
Disassembly of Traction Pump . . . . . . . . . . . . . 32
Cutting Units Will Not Drop
Assembly of Traction Pump. . . . . . . . . . . . . . . . 34
or Follow Ground Contours . . . . . . . . . . . . . . 17
Auxiliary/Steering Pump Repairs. . . . . . . . . . . . 36
Cutting Unit(s) Drop From Raised Position
Front Traction Motor Repairs. . . . . . . . . . . . . . . 40
With Lift Valve in Centered Position . . . . . . . 17
Rear Axle 4wd Motor Repairs . . . . . . . . . . . . . . 46
Cutting Unit(s) Lower or Raise Too Quickly. . . . 18
Lift Valve Repairs. . . . . . . . . . . . . . . . . . . . . . . . 48
Steering Loss . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Steering Control Unit Repairs . . . . . . . . . . . . . . 50
Hydraulic System
Groundsmaster
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455-D Page 4 - 1 Table of Contents