Toro Groundsmaster 4500-D Series Service Manual page 103

Table of Contents
General Information .............................................................................................................................. 5-3
Operator's Manual ............................................................................................................................. 5-3
Check Hydraulic Fluid ........................................................................................................................ 5-3
Towing Traction Unit........................................................................................................................... 5-3
Relieving Hydraulic System Pressure ................................................................................................ 5-4
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..................................................................................................................... 5-14
Traction Circuit: LOW Mode............................................................................................................. 5-15
Traction Circuit: Auto Mode ............................................................................................................. 5-17
Lower Cutting Decks: Groundsmaster 4500-D ................................................................................ 5-20
Lower Cutting Decks: Groundsmaster 4700-D ................................................................................ 5-23
Raise Cutting Decks: Groundsmaster 4500-D ................................................................................. 5-26
Raise Cutting Decks: Groundsmaster 4700-D ................................................................................. 5-29
Mow Circuit ...................................................................................................................................... 5-32
Cutting Deck Blade Braking ............................................................................................................. 5-35
Steering Circuit ................................................................................................................................ 5-37
Engine Cooling Fan Circuit .............................................................................................................. 5-40
Testing ................................................................................................................................................. 5-43
Precautions for Hydraulic Testing..................................................................................................... 5-43
Which Hydraulic Tests Are Necessary?............................................................................................ 5-44
Traction Circuit Charge Pressure (Using Pressure Gauge) .............................................................. 5-46
Traction Circuit Relief Pressure (Using Pressure Gauge)................................................................. 5-49
Reverse Traction Circuit Reducing Valve (PR) Pressure (Using Pressure Gauge)............................ 5-53
Rear Traction Circuit Relief (RV) Pressure (Using Pressure Gauge) ................................................ 5-56
Piston (Traction) Pump Flow (Using Tester with Pressure Gauge & Flow Meter)............................... 5-59
Cutting Deck Circuit Pressure (Using Pressure Gauge) ................................................................... 5-62
Cutting Deck Circuit Relief Pressure (Using Tester with Pressure Gauge & Flow
Meter)............................................................................................................................................... 5-65
Deck Motor Case Drain Leakage (Using Tester with Pressure Gauge & Flow
Meter)............................................................................................................................................... 5-68
Steering Circuit Relief Pressure (Using Pressure Gauge) ................................................................ 5-71
Steering Cylinder Internal Leakage .................................................................................................. 5-74
Lift/Lower Circuit Relief Pressure (Using Pressure Gauge) .............................................................. 5-76
Engine Cooling Fan Circuit (Using Pressure Gauge and Phototac) .................................................. 5-79
Gear Pump Flow (Using Tester with Pressure Gauge & Flow Meter) ................................................ 5-82
Procedure for Gear Pump Flow Test ................................................................................................ 5-83
Adjustments ........................................................................................................................................ 5-86
Adjust Control Manifold Relief Valves............................................................................................... 5-86
Service and Repairs ........................................................................................................................... 5-87
General Precautions for Removing and Installing Hydraulic System Components ........................... 5-87
Check Hydraulic Lines and Hoses ................................................................................................... 5-89
Priming Hydraulic Pumps................................................................................................................. 5-90
Flush Hydraulic System ................................................................................................................... 5-91
Filtering Closed−Loop Traction Circuit ............................................................................................. 5-93
Groundsmaster ® 4500-D/4700-D
19245SL Rev A
Hydraulic System
Page 5-1
Chapter 5
Hydraulic System