Kubota RT250-2, and RT260-2 Service Manual — TOB-0086841

About this manual

Kubota published this Service Manual for RT250-2 and RT260-2. It is intended for maintenance, source-supported service, and source-supported repair, where those subjects appear in the source publication.

Use the Manual Contents below to check that the exact maintenance, inspection, service, or repair procedure you need is included in this publication.

Manual details

Manufacturer

Kubota

Manual type

Service Manual

Models

RT250-2 and RT260-2

Document number

TOB-0086841

Publication year

2023

Language

English

Page count

243

Product highlights

Electrical systems

The manual includes wiring diagrams and electrical troubleshooting.

Hydraulic systems

The manual includes hydraulic circuit diagrams and hydraulic pressure-test material.

Specifications and settings

The manual includes reference information for pressure specifications.

Special tools

A special-tools section is included.

Maintenance

The manual includes a maintenance schedule.

Manual contents

Use these source headings to locate the task or system you need in the PDF.

• Preface — p. 3
  • Language — p. 3
  • Related documents — p. 4
  • OEM documentation overview — p. 4
  • Icons and signal words used in the document — p. 5
  • Tools — p. 5
  • Illustrations — p. 6
  • Version history — p. 6
  • Typographical conventions — p. 7
  • Abbreviations — p. 7
  • Terminology — p. 8
• 1 Safety — p. 15
  • 1.1 Service-related safety instructions — p. 15
    • 1.1.1 General safety instructions — p. 15
    • 1.1.2 Safety instructions for service on the transmission — p. 15
    • 1.1.3 Safety instructions for service below the lifting arm — p. 15
  • 1.2 Approved trainer — p. 16
  • 1.3 Approved service engineer — p. 16
• 2 Description — p. 17
  • 2.1 Engine — p. 17
    • 2.1.1 Overview — p. 17
    • 2.1.2 Lubrication system — p. 18
    • 2.1.3 Cooling system — p. 19
  • 2.2 Electrical system — p. 19
    • 2.2.1 Schematic overview — p. 19
    • 2.2.2 Electrical diagram — p. 20
    • 2.2.3 Fuses and relays — p. 20
      • 2.2.3.1 Fuses in steering column — p. 21
      • 2.2.3.2 Fuses in dashboard — p. 21
      • 2.2.3.3 Fuses in driver's seat — p. 22
    • 2.2.4 Ground and power connections — p. 22
  • 2.3 Hydraulic system — p. 24
    • 2.3.1 Hydraulic diagram — p. 24
    • 2.3.2 Overview of the drive hydraulics — p. 25
    • 2.3.3 Overview of the steering hydraulics — p. 26
    • 2.3.4 Overview of the work hydraulics — p. 27
    • 2.3.5 Drive pump — p. 28
    • 2.3.6 Drive motor — p. 28
    • 2.3.7 Work pump — p. 29
    • 2.3.8 Fuel feed pump — p. 29
    • 2.3.9 Fuel supply pump — p. 30
    • 2.3.10 Main control valve — p. 30
    • 2.3.11 Hydraulic cylinders — p. 33
    • 2.3.12 Steering cylinder — p. 33
    • 2.3.13 Steering unit and priority valve — p. 33
    • 2.3.14 Attachment lock cylinder — p. 35
    • 2.3.15 6/2-diverter valve (If applicable) — p. 36
  • 2.4 Transmission and wheels — p. 37
    • 2.4.1 Overview — p. 37
    • 2.4.2 Brake and inching system — p. 38
• 3 Maintenance — p. 41
  • 3.1 General maintenance instructions — p. 41
  • 3.2 Performing a test drive — p. 42
  • 3.3 Ordering parts — p. 42
  • 3.4 Servicing below the lifting arm — p. 42
    • 3.4.1 Installing the safety bracket on the RT250-2/RT260-2 — p. 42
    • 3.4.2 Storing the safety bracket on the RT250-2/RT260-2 — p. 43
  • 3.5 Accessing parts — p. 44
    • 3.5.1 Opening the bonnet — p. 44
    • 3.5.2 Accessing the work hydraulics (top side) — p. 44
    • 3.5.3 Accessing the steering unit — p. 44
    • 3.5.4 Accessing the brakes — p. 45
    • 3.5.5 Tilting the cabin/canopy — p. 46
  • 3.6 Panolin synthetic hydraulic oil (If applicable) — p. 48
    • 3.6.1 Requirements — p. 48
    • 3.6.2 Sample method — p. 48
    • 3.6.3 Test intervals — p. 49
  • 3.7 Maintenance schedule — p. 49
    • 3.7.1 Maintenance: quick reference — p. 49
    • 3.7.2 Maintenance before delivery — p. 52
    • 3.7.3 Maintenance after the first 50 hours — p. 55
    • 3.7.4 Maintenance after every 250 hours — p. 57
    • 3.7.5 Maintenance every 500 hours — p. 58
    • 3.7.6 Maintenance every 1000 hours — p. 59
    • 3.7.7 Maintenance every 1500 hours — p. 60
    • 3.7.8 Maintenance every 3000 hours — p. 61
    • 3.7.9 Maintenance every 1 year — p. 61
    • 3.7.10 Maintenance every 2 years — p. 63
  • 3.8 Maintenance tasks — p. 63
    • 3.8.1 Engine — p. 63
    • 3.8.2 Cooling system — p. 65
    • 3.8.3 Fuel system — p. 65
    • 3.8.4 Hydraulic system — p. 65
    • 3.8.5 Electrical system — p. 67
    • 3.8.6 Cabin and controls — p. 67
    • 3.8.7 Transmission and wheels — p. 68
    • 3.8.8 Frame — p. 70
• 4 Checks, cleaning and functional tests — p. 71
  • 4.1 Cabin and controls — p. 71
    • 4.1.1 Checking the ROPS-FOPS structure — p. 71
    • 4.1.2 Checking the windscreen wiper blades (If applicable) — p. 72
    • 4.1.3 Testing the steering system — p. 72
    • 4.1.4 Checking the steering wheel — p. 72
    • 4.1.5 Testing the steering column — p. 72
    • 4.1.6 Checking the steering column lock — p. 72
    • 4.1.7 Testing the radio (If applicable) — p. 73
    • 4.1.8 Testing the driver's seat — p. 73
    • 4.1.9 Testing the 12-V connection (If applicable) — p. 73
    • 4.1.10 Testing the rotating beacon (If applicable) — p. 73
    • 4.1.11 Testing the heater (optional) — p. 73
    • 4.1.12 Checking OPM (operator manual) presence — p. 73
  • 4.2 Engine, cooling and fuel system — p. 74
    • 4.2.1 Cleaning the main air filter — p. 74
    • 4.2.2 Checking the exhaust system — p. 75
    • 4.2.3 Checking the fuel hoses — p. 76
    • 4.2.4 Checking the V-belt — p. 76
    • 4.2.5 Checking the cable connectors — p. 76
    • 4.2.6 Checking the vibration dampers — p. 77
  • 4.3 Electrical system — p. 77
    • 4.3.1 Checking the electrical wiring — p. 77
  • 4.4 Hydraulic system — p. 78
    • 4.4.1 Checking the hydraulic cylinder scraper — p. 78
    • 4.4.2 Testing the cylinder seals — p. 78
    • 4.4.3 Testing the lifting arm displacements — p. 79
  • 4.5 Transmission and wheels — p. 80
    • 4.5.1 Checking the front axle oil level — p. 80
    • 4.5.2 Checking the rear axle oil level — p. 81
    • 4.5.3 Cleaning the axle breather plugs — p. 82
    • 4.5.4 Checking the wheel hub oil level — p. 83
    • 4.5.5 Checking gearbox oil level — p. 84
    • 4.5.6 Testing the braking system — p. 85
  • 4.6 Frame — p. 85
    • 4.6.1 Checking the paintwork — p. 85
    • 4.6.2 Checking the attachment lock position — p. 85
    • 4.6.3 Checking the cabin vibration dampers — p. 86
    • 4.6.4 Checking the hinge pin bolts — p. 87
    • 4.6.5 Checking the hinge pin spring pins — p. 87
• 5 Measurements — p. 89
  • 5.1 Cabin and controls — p. 89
    • 5.1.1 Measuring the front automotive lights inclination — p. 89
  • 5.2 Engine, cooling and fuel system — p. 89
    • 5.2.1 Measuring the coolant freezing point — p. 89
    • 5.2.2 Measuring the valve clearance — p. 90
    • 5.2.3 Measuring the V-belt tension — p. 90
    • 5.2.4 Measuring the glow plugs continuity — p. 90
    • 5.2.5 Measuring the idle speed — p. 90
    • 5.2.6 Measuring the thermostat valve opening temperature — p. 90
  • 5.3 Electrical system — p. 91
    • 5.3.1 Measuring the battery voltage — p. 91
    • 5.3.2 Measuring the alternator supply voltage — p. 92
  • 5.4 Hydraulic system — p. 93
    • 5.4.1 Measuring the drive pump boost pressure — p. 93
    • 5.4.2 Measuring the drive pump forward pressure — p. 94
    • 5.4.3 Measuring the drive pump reverse pressure — p. 95
    • 5.4.4 Measuring the main work pressure — p. 96
      • 5.4.4.1 Measuring the main work pressure (With pressure gauge) — p. 96
    • 5.4.5 Measuring the steering pressure — p. 97
  • 5.5 Transmission and wheels — p. 98
    • 5.5.1 Measuring the brake shoes wear — p. 98
• 6 Adjustments — p. 99
  • 6.1 Cabin and controls — p. 99
    • 6.1.1 Adjusting the front automotive lights inclination — p. 99
  • 6.2 Engine, cooling and fuel system — p. 100
    • 6.2.1 Bleeding the fuel system — p. 100
    • 6.2.2 Draining the fuel tank — p. 101
    • 6.2.3 Adjusting the V-belt tension — p. 101
    • 6.2.4 Adjusting the idle speed — p. 102
  • 6.3 Electrical system — p. 103
    • 6.3.1 Charging the battery — p. 103
  • 6.4 Hydraulic system — p. 104
    • 6.4.1 Adjusting the drive pump boost pressure — p. 104
    • 6.4.2 Adjusting the drive pump pressure cut-off — p. 105
    • 6.4.3 Adjusting the main work pressure — p. 106
    • 6.4.4 Adjusting the tilt cylinder load-holding valve — p. 107
    • 6.4.5 Adjusting the lift cylinder load-holding valve — p. 108
  • 6.5 Transmission and wheels — p. 109
    • 6.5.1 Adding oil to the front axle — p. 109
    • 6.5.2 Adding oil to the rear axle — p. 110
    • 6.5.3 Adding oil to a wheel hub — p. 111
    • 6.5.4 Adding oil to the gearbox — p. 113
• 7 Replacements — p. 115
  • 7.1 Cabin and controls — p. 115
    • 7.1.1 Replacing the safety roof — p. 115
      • 7.1.1.1 Replacing the canopy — p. 115
      • 7.1.1.2 Replacing the cabin — p. 118
      • 7.1.1.3 Replacing the foldable roof — p. 123
    • 7.1.2 Replacing the steering wheel — p. 125
    • 7.1.3 Replacing the steering column — p. 126
    • 7.1.4 Replacing the dashboard — p. 128
    • 7.1.5 Replacing the switch panel — p. 129
    • 7.1.6 Replacing the driver's seat — p. 129
    • 7.1.7 Replacing the windscreen wiper blades (If applicable) — p. 131
    • 7.1.8 Replacing the radio (If applicable) — p. 131
    • 7.1.9 Replacing the joystick — p. 131
  • 7.2 Engine, cooling and fuel system — p. 133
    • 7.2.1 Replacing the engine oil — p. 133
    • 7.2.2 Replacing the engine oil filter — p. 135
    • 7.2.3 Replacing the fuel filter(s) — p. 136
    • 7.2.4 Replacing the main air filter and the safety air filter — p. 137
    • 7.2.5 Replacing the complete air filter unit — p. 138
    • 7.2.6 Replacing the coolant — p. 140
      • 7.2.6.1 Antifreeze — p. 141
    • 7.2.7 Replacing parts of the cooling system — p. 143
    • 7.2.8 Replacing the combination cooler — p. 144
    • 7.2.9 Replacing the V-belt — p. 147
    • 7.2.10 Replacing the glow plug — p. 148
    • 7.2.11 Replacing the vibration dampers — p. 150
    • 7.2.12 Replacing the fuel hoses — p. 151
    • 7.2.13 Replacing the fuel feed pump — p. 152
    • 7.2.14 Replacing the thermostat — p. 152
    • 7.2.15 Replacing the pressure-relief valve of the combination cooler — p. 153
    • 7.2.16 Replacing the combustion engine — p. 153
    • 7.2.17 Replacing the impeller — p. 154
    • 7.2.18 Replacing the starter motor — p. 155
  • 7.3 Electrical system — p. 155
    • 7.3.1 Replacing the battery — p. 155
    • 7.3.2 Replacing the battery switch — p. 157
    • 7.3.3 Replacing the alternator — p. 158
  • 7.4 Hydraulic system — p. 159
    • 7.4.1 Replacing the hydraulic oil — p. 159
    • 7.4.2 Replacing the complete hydraulic filter — p. 161
    • 7.4.3 Replacing the hydraulic oil tank filler cap — p. 162
    • 7.4.4 Replacing the work pump — p. 162
    • 7.4.5 Replacing the double work pump (optional) — p. 163
    • 7.4.6 Replacing the drive pump — p. 165
    • 7.4.7 Replacing the drive motor — p. 167
    • 7.4.8 Replacing the steering unit — p. 169
    • 7.4.9 Replacing the main control valve — p. 170
    • 7.4.10 Replacing the hydraulic hoses — p. 172
    • 7.4.11 Replacing the hydraulic cylinders — p. 173
      • 7.4.11.1 Replacing the lift cylinder — p. 173
      • 7.4.11.2 Replacing the tilt cylinder — p. 175
      • 7.4.11.3 Replacing the steering cylinder — p. 176
      • 7.4.11.4 Replacing the attachment lock cylinder — p. 178
    • 7.4.12 Replacing the cylinder seals — p. 179
      • 7.4.12.1 Replacing the lift cylinder seals — p. 179
      • 7.4.12.2 Replacing the tilt cylinder seals — p. 182
      • 7.4.12.3 Replacing the steering cylinder seals — p. 184
    • 7.4.13 Replacing (parts of) the MCO manifold (If applicable) — p. 187
  • 7.5 Transmission and wheels — p. 188
    • 7.5.1 Replacing the throttle cable — p. 188
    • 7.5.2 Replacing the drive shaft — p. 189
    • 7.5.3 Replacing the monolastic elastic clutch — p. 190
    • 7.5.4 Replacing the front axle — p. 191
    • 7.5.5 Replacing the front axle oil — p. 193
    • 7.5.6 Replacing the rear axle — p. 194
    • 7.5.7 Replacing the rear axle oil — p. 196
    • 7.5.8 Replacing the wheel hubs axle oil — p. 197
    • 7.5.9 Replacing the gearbox oil — p. 199
    • 7.5.10 Replacing the brake fluid — p. 201
    • 7.5.11 Bleeding the braking system — p. 202
      • 7.5.11.1 Bleeding the braking system (Method 1) — p. 202
      • 7.5.11.2 Bleeding the braking system (Method 2) — p. 203
    • 7.5.12 Replacing the brake shoes — p. 204
  • 7.6 Frame — p. 206
    • 7.6.1 Replacing ball joints — p. 206
      • 7.6.1.1 Replacing top ball joint — p. 206
      • 7.6.1.2 Replacing lower ball joint — p. 211
    • 7.6.2 Replacing the bonnet — p. 215
    • 7.6.3 Replacing the standard lifting arm — p. 216
• 8 Troubleshooting — p. 221
  • 8.1 Troubleshooting procedure — p. 221
  • 8.2 Complete machine — p. 221
    • 8.2.1 Troubleshooting table — p. 221
  • 8.3 Cabin and controls — p. 221
    • 8.3.1 Troubleshooting table — p. 221
  • 8.4 Engine, cooling and fuel system — p. 222
    • 8.4.1 Troubleshooting table — p. 222
  • 8.5 Electrical system — p. 222
    • 8.5.1 Troubleshooting table — p. 222
  • 8.6 Hydraulic system — p. 223
    • 8.6.1 Troubleshooting table — p. 223
    • 8.6.2 Forward or reverse drive pressure incorrect — p. 224
    • 8.6.3 Tilt cylinder displacement outside of specifications — p. 225
    • 8.6.4 Lift cylinder displacement outside of specifications — p. 226
• 9 Technical Data — p. 227
  • 9.1 Consumables — p. 227
    • 9.1.1 Fluid specifications — p. 227
  • 9.2 Torque specifications — p. 227
    • 9.2.1 Torque specifications of fasteners — p. 227
    • 9.2.2 Torque specifications of special fasteners — p. 228
  • 9.3 Clearance specifications — p. 228
  • 9.4 Paint specifications — p. 229
  • 9.5 Non-Destructive Testing (NDT) inspection standards — p. 229
  • 9.6 Wear specifications — p. 229
  • 9.7 Pressure specifications — p. 229
  • 9.8 Other specifications — p. 230
  • 9.9 Special tools specifications — p. 230
• 10 OEM Documentation — p. 231
  • 10.1 Checks, cleaning and functional tests — p. 231
    • 10.1.1 Check V-belt — p. 231
  • 10.2 Measurements and adjustments — p. 232
    • 10.2.1 Measuring and adjusting the valve clearance — p. 232
    • 10.2.2 Measuring and adjusting the V-belt tension — p. 233
    • 10.2.3 Measuring the thermostat opening temperature — p. 234
    • 10.2.4 Measuring the alternator supply voltage — p. 235
    • 10.2.5 Measuring the glow plugs continuity — p. 235
  • 10.3 Replacements — p. 236
    • 10.3.1 Replacing the V-belt — p. 236
    • 10.3.2 Replacing the thermostat — p. 237
  • 10.4 OEM-troubleshooting — p. 237
    • 10.4.1 Electric — p. 237
      • 10.4.1.1 Bearing — p. 238
      • 10.4.1.2 Stator — p. 238
      • 10.4.1.3 Rotor — p. 239
      • 10.4.1.4 Slip ring — p. 240
      • 10.4.1.5 Brush wear — p. 241
      • 10.4.1.6 Rectifier — p. 242
      • 10.4.1.7 IC-regulator — p. 242

Capabilities

The source outline indexes servicing instructions, maintenance, checking and adjustment, replacement procedures, troubleshooting, and inspection. Use these source-backed headings to locate the applicable service or repair topic in the source PDF, then confirm model-specific notes, specifications, illustrations, and operating conditions at the relevant page before carrying out service or repair work.

Keep the source's safety sequence, prerequisite steps, labels, units, configuration notes, and footnotes with the selected task; do not apply an isolated value outside the conditions stated in the manual.

Technical reference

Reference tables include pressure specifications for service specifications, limits, adjustment and repair reference data. Use the values and conditions in the PDF for the applicable model and procedure.

• Pressure reference: pressure specifications.

Delivery

This manual is supplied as a digital PDF file and is available for instant download after purchase. No physical media is shipped.

References

Kubota Service Manual for Wheel Loader, document code TOB-0086841, PDF edition.