Chapter 5: Hydraulic System - Toro Groundsmaster 5900 Series Service Manual

Table of Contents
General Information .............................................................................................................................. 5-3
Operator's Manual ............................................................................................................................. 5-3
Relieving Hydraulic System Pressure ................................................................................................ 5-3
Towing Traction Unit........................................................................................................................... 5-3
Traction Circuit Component Failure.................................................................................................... 5-5
Hydraulic Hoses................................................................................................................................. 5-6
Installing Hydraulic Hoses and Tubes (O-Ring Face Seal) ................................................................. 5-7
Installing the Hydraulic Fittings (SAE Straight Thread O-Ring Fittings)............................................... 5-9
Hydraulic Schematic............................................................................................................................ 5-12
Hydraulic Flow Diagrams..................................................................................................................... 5-13
Traction Circuit Operation ................................................................................................................ 5-14
Traction Circuit: Low Range Traction Speed (Mow) ......................................................................... 5-16
Traction Circuit: High Range Traction Speed (Transport)................................................................. 5-19
Raise Cutting Deck .......................................................................................................................... 5-22
Lower Cutting Deck.......................................................................................................................... 5-25
PTO Mow Circuit .............................................................................................................................. 5-28
PTO Mow Circuit Cutting Deck Blade Braking.................................................................................. 5-31
Steering Circuit ................................................................................................................................ 5-33
Testing ................................................................................................................................................. 5-36
Before Performing Hydraulic Tests................................................................................................... 5-36
Precautions for Hydraulic Testing..................................................................................................... 5-36
Which Hydraulic Tests Are Necessary?............................................................................................ 5-37
Traction Circuit Charge Pressure Test (Using Pressure Gauge) ....................................................... 5-39
Traction Circuit Relief Pressure Test (Using Pressure Gauge) ......................................................... 5-42
Counterbalance Pressure Test (Using Pressure Gauge).................................................................. 5-45
Piston (Traction) Pump Flow Test (Using Tester with Pressure Gauge & 40 GPM Flow
Meter)............................................................................................................................................... 5-47
Cutting Deck Circuit Pressure Test (Using Pressure Gauge) ............................................................ 5-50
Cutting Deck Circuit Relief Pressure Test (Using Tester with Pressure Gauge and 40 GPM Flow
Meter)............................................................................................................................................... 5-53
Cutting Deck Motor Case Drain Leakage Test (Using Tester with Pressure Gauge & 40 GPM Flow
Meter)............................................................................................................................................... 5-56
Lift/Lower Circuit Relief Pressure Test (Using Pressure Gauge)....................................................... 5-60
Steering Circuit Relief Pressure Test (Using Pressure Gauge) ......................................................... 5-63
Steering Cylinder Internal Leakage Test........................................................................................... 5-65
Gear Pump (PTO, Steering, Deck Lift/Lower and Traction Charge Circuits) Flow Test (Using
Tester with Pressure Gauges and Flow Meter)................................................................................. 5-67
Adjustments ........................................................................................................................................ 5-72
Adjust Manifold Relief Valves ........................................................................................................... 5-72
Service and Repairs ........................................................................................................................... 5-73
General Precautions for Removing and Installing Hydraulic System Components ........................... 5-73
Check Hydraulic Lines and Hoses ................................................................................................... 5-75
Priming Hydraulic Pumps................................................................................................................. 5-76
Flush Hydraulic System ................................................................................................................... 5-77
Charge Hydraulic System ................................................................................................................ 5-79
Filtering Closed−Loop Traction Circuit ............................................................................................. 5-81
Hydraulic Reservoir.......................................................................................................................... 5-83
Gear Pump....................................................................................................................................... 5-86
Groundsmaster ® 5900 & 5910
16227SL Rev B
Hydraulic System
Page 5-1
Chapter 5
Hydraulic System