Chapter 4: Hydraulic System - Toro Greensmaster 3120 Service Manual

Table of Contents
Specifications ....................................................................................................................................... 4-3
Hydraulic System ............................................................................................................................... 4-3
General Information .............................................................................................................................. 4-4
Traction Unit Operator's Manual ........................................................................................................ 4-4
Relieving Pressure from the Hydraulic System .................................................................................. 4-4
Towing the Traction Unit..................................................................................................................... 4-5
Traction Circuit (Closed Loop) Component Failure............................................................................. 4-6
Hydraulic Hoses................................................................................................................................. 4-7
Installing Hydraulic Hoses and Tubes (O-Ring Face Seal) ................................................................. 4-8
Installing the Hydraulic Fittings (SAE Straight Thread O-Ring Fittings)............................................. 4-10
Hydraulic Schematics .......................................................................................................................... 4-13
Hydraulic Flow Diagrams..................................................................................................................... 4-15
Traction Circuit ................................................................................................................................. 4-15
Lift Circuit ......................................................................................................................................... 4-17
Mow Circuit ...................................................................................................................................... 4-20
Steering Circuit ................................................................................................................................ 4-24
Special Tools ....................................................................................................................................... 4-26
Hydraulic Pressure Testing Kit ......................................................................................................... 4-26
Hydraulic Tester Kit .......................................................................................................................... 4-26
Hydraulic Test Fitting Kit................................................................................................................... 4-27
O-Ring Kit ........................................................................................................................................ 4-28
Hydraulic Hose Kit ........................................................................................................................... 4-28
Measuring Container ....................................................................................................................... 4-28
High Flow Hydraulic Filter Kit ........................................................................................................... 4-29
Troubleshooting................................................................................................................................... 4-30
General Hydraulic System Problems ............................................................................................... 4-30
Traction Circuit Problems ................................................................................................................. 4-31
Mow Circuit Problems ...................................................................................................................... 4-32
Lift/Lower Circuit Problems .............................................................................................................. 4-33
Steering Circuit Problems ................................................................................................................ 4-34
Testing the Hydraulic System .............................................................................................................. 4-35
Hydraulic Test Selection................................................................................................................... 4-37
Traction Circuit Testing - Charge Pressure Test............................................................................... 4-38
Traction Circuit Testing - Wheel Motor Efficiency Test...................................................................... 4-44
Traction Circuit Testing - Traction Pump (P1) Flow and Relief Pressure Test.................................... 4-47
Cutting Unit Circuit Testing - Cutting Unit Motor Efficiency/Case Drain Test ..................................... 4-50
Cutting Unit Circuit Testing - Relief Valve Test ................................................................................. 4-53
Cutting Unit Circuit Testing - Gear Pump (P2) Flow Test .................................................................. 4-56
Steering/Lift Circuit Testing - Gear Pump (P3) Flow and Circuit Relief Valve
Test .................................................................................................................................................. 4-59
Steering/Lift Circuit Testing - Lowering Cutting Units Relief Valve Test............................................. 4-63
Steering/Lift Circuit Testing - Steering Control Valve and Steering Cylinder Test .............................. 4-67
Adjustments ........................................................................................................................................ 4-70
Adjusting Relief Valves..................................................................................................................... 4-70
Service and Repairs ........................................................................................................................... 4-71
General Precautions for Removing and Installing the Hydraulic System Components...................... 4-71
Checking the Hydraulic Lines and Hoses ......................................................................................... 4-73
Flushing the Hydraulic System......................................................................................................... 4-74
Greensmaster 3120
17230SL Rev C
Hydraulic System
Page 4-1
Chapter 4
Hydraulic System