This is the official Kubota B21, TL421, and BT751 workshop manual, a 437-page PDF for the B21 compact tractor, TL421 front loader, and BT751 backhoe. It carries the D1005-ETLB engine and is split into Mechanism and Servicing parts, so you first learn how each system works, then follow the service procedures.
Coverage runs from the engine, clutch, transmission, and rear axle through the brakes, front axle, steering, hydraulic system, and full electrical system, plus dedicated Front Loader and Backhoe sections. Each area includes troubleshooting, factory specifications, allowable limits, and disassembly and assembly steps.
This is the manual for real shop work: setting valve clearance, chasing a hydraulic or electrical fault, torquing fasteners to spec, and rebuilding the loader or backhoe rather than guessing at it.
Complete the set for your B21, TL421, BT751
- Parts Catalog: Kubota B21 Parts Manual
- Parts Catalog: Kubota BT751 Backhoe Parts Catalog PDF
- Parts Catalog: Kubota TL421 Loader Parts Catalog
What's Inside This Kubota B21, TL421, BT751 Manual
| System | Pages | Key Topics |
|---|---|---|
| To the Reader | Kubota Tractor B21, Kubota Front Loader TL421, Kubota Backhoe BT751, PTO, Engine, Hydraulic, Clutch, Transmission | |
| General | Tractor Identification, Electrical Parts and Wiring, Lubricants, Fuel and Cooling Water, Screws, Bolts and Nuts, Stud Bolts, Hydraulic Hoses Fitting | |
| Engine | Cylinder Block, Cylinder Head, Crankshaft, Piston and Piston Rings, Connecting Rod, Camshaft, Fuel Camshaft, Rocker Arm | |
| Clutch | Linkage Mechanism, Operation, Clutch Disc, Pressure Plate Assembly, Release Bearing, Release Hub, Release Fork | |
| Transmission | Hydrostatic Transmission, PTO System, Differential Gear System, Clutch Housing, Transmission Case, Differential Case | |
| Rear Axle | Differential Gear Shaft, Ball Bearing, Rear Axle Case, Spur Gear, Differential, Spiral Bevel Gear, Differential Lock Shift Fork | |
| Brakes | Brake Pedal, Rear Axle Case, Differential Lock Shift Fork, Differential Lock Clutch, 57T Gear, Brake Assembly, Brake Discs, Friction Plate | |
| Front Axle | Front Wheel Alignment, Propeller Shaft, Drag Link, Front Axle Assembly, Tie-Rod, Axle Bracket, Bevel Gear Case | |
| Steering | Hydraulic Circuit, Power Steering Body, Drag Link, Pitman Arm, Power Steering Assembly, Ball Nut Assembly, Valve Housing, Sector Gear Shaft | |
| Hydraulic System | Hydraulic Pump, Flow Priority Valve, Position Control Valve, Hydraulic Block, Hydraulic Cylinder, Relief Valve, Hydraulic Piston, Lowering Speed Adjusting Valve | |
| Electrical System | Wiring Diagram and Electrical Circuit, Starting System, Engine Key Switch Shut-Off System, Charging System, Lighting System, Easy Checker, Gauge, Opc(operator Presence Control)system | |
| Front Loader | Safety Decals, Front Loader Terminology, Operating Dimensions, Hydraulic System, Control Valve Assembly, Feedback Linkage, Boom Cylinder, Bucket Cylinder | |
| Backhoe | Safety Decals, Backhoe Terminology, Operating Dimensions, Cycle Time, Hydraulic Cylinders, Lift Capacity, Hydraulic System, Hydraulic Cylinder |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| TL421 | ||
| Loader side frame mounting screw, bolt and nut tightening torque | 150 to 160 N·m | p. 393 |
| B21 | ||
| Hydraulic oil filter for HST, efficiency | 10 µm | p. 26 |
| Transmission case (Hydraulic Fluid) Capacity | 27.5 L | p. 20 |
| Fan belt tension | 7 to 9 mm (0.28 to 0.34 in.) deflection | p. 35 |
| Battery Cold Cranking Amps | 433 A | p. 33 |
| Main Switch Continuity (ON Position, 30 terminal - AC terminal) | 0 ohm | p. 339 |
| Fuse Capacity (Head lights) | 10 A | p. 41 |
| Main Switch Connector 30 terminal voltage | Approx. battery voltage | p. 339 |
| Thermostat Valve Opening Temperature (At Beginning) | 80.5 to 83.5 °C | p. 134 |
| PTO Power | 10.0 kW (13.5 HP) | p. 8 |
| Engine Oil Capacity (with filter) | 3.0 L | p. 8 |
