Part of the Kubota Repair Manuals.
This Kubota workshop manual covers the R420α, R520α, R420S, and R520S wheel loaders, including the interim Tier 4 and Stage III A emissions engine variants. It is the combined mechanism and service edition, publication number 97899-62060, running 820 pages with a full text layer.The manual documents every major system on these machines: engine, hydraulics and the LST pump circuit, brakes and power train, the electrical system, and the backhoe attachment. Specification tables, service intervals, tightening torques, and step by step disassembly procedures are all included.With it you can diagnose a fault, follow the correct teardown sequence, set clearances to spec, and reassemble with confidence, whether you are an owner doing your own maintenance or a mechanic servicing these loaders professionally.
What's Inside This Kubota R420–R520 Series Manual
| System | Pages | Key Topics |
|---|---|---|
| I. General | 5-28 | Body and Engine Identifications Marks, Safety Precautions for Servicing, Disassembly and Reassembly (a) Safety Measures Before Starting Work, B) Safety Measures During Work |
| Ii. Machine BODY-Mechanism | 29-55 | Machine Specifications (a) Specification Table, B) Specification Table, Backhoe-Version, C) Lifting Capacity), Development Concept of Model Change (a) Two Main Concepts |
| Ii. Machine Body & Front Attachment-Service | 56-117 | Machine Specifications (a) Specification Table: PP-version, B) Main Specification: EU-version, C) Dimensional Specifications, D) Specification Table: Backhoe, E) Parts Weight Table |
| Iii. ENGINE-Mechanism | 118-135 | Engine Specifications, Engine Performance Curve, New Emissions Control Engines (a) Outline, B) Engine List for Minor Change |
| Iii. ENGINE-Service | 136-354 | Specifications, Engine Assy Dismounting, Engine Accessories (a) Engine Rubber Mount, B) Radiator, Oil Cooler, C) Air Cleaner, D) Muffler, E) Muffler Installation |
| Iv. Hydraulic SYSTEM-Mechanism | 355-391 | Circuit Diagram & Components (a) Hydraulic Circuit Diagram, B) Components Layout), Lst Pump (a) Function of Lst Pump, B) Servo Cylinder, C) High-Pressure Relief Valve |
| Iv. Hydraulic System-Service | 392-573 | Troubleshooting (a) Hydraulic System Does Not Work, B) Weak Lifting, Any Circuit, C) Slow Lifting, D) Cylinder Fall, E) Does Not Travel in Both the F and R Directions |
| V. Brake System and Power Train-Mechanism | 574-589 | Outline, Parking Brake, Service Brake: Axle Brake, Negative Brake Releasing Method, Power Train Components (a) Front Differential Axle Shaft Assy |
| V. Brake System and Power Train-Service | 590-617 | Brake System (a) Negative Brake, B) Parking Valve), Power Train (a) Front Axle, B) Rear Axle, C) Differential Gear, D) Reduction Gear Case Assembly, E) Differential Ass'y Assembly |
| Vi. Electrical System-Mechanism | 618-623 | (A) Electrical Wiring: R420S/Α, R520S/Α, (B) Electrical Circuit Diagram |
| Vi. Electrical System-Service | 624-689 | Testing, Troubleshooting (a) Battery Discharges Quickly, B) Starter Does Not Drive Engine Properly, C) Forward and Reverse Run Not Selectable, D) Low-Speed Hold Not Effective |
| Vii. BACKHOE-Mechanism | 690-695 | (A) Oil Flow Chart of Backhoe, (B) Hydraulic Circuit Diagram |
| Vii. BACKHOE-Service | 696-743 | Specifications (a) General Dimension, B) Operating Performance, C) Lifting Capacity, D) Hydraulic System Data, E) Bucket, Boom, Arm Data, F) Pin and Bushing Dimensions) |
| Viii. Supplement | 744-815 | Fundamentals of Wheel Loader (a) Glossary, B) Relevant Performance Data), Introduction of Lst System, Introduction of Steering System (a) Steering Performance |
| Conversion Tables | 816-820 | - |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Battery liquid level check interval | Every 50 hrs | p. 16 |
| Fuel tank drain interval | Every 50 hrs | p. 16 |
| Hydraulic Oil Tank Capacity | 42 L (11.1 U.S.gals) | p. 59 |
| Fuel Tank Capacity | 54 L (14.3 U.S.gals) | p. 18 |
| Hose Screw Tightening Torque (1/8" Union nut section) | 7.8 ~ 11.8 N-m | p. 21 |
| M6 Bolt Tightening Torque (Standard Screw and Bolt) | 7.9 ~ 9.3 N-m | p. 24 |
| Engine Valve Clearance (When Cold) | 0.18 to 0.22 mm | p. 257 |
| R420S, R420α | ||
| Engine Oil Capacity (124 mm oil pan depth) | 7.0 L (1.8 U.S.gals) | p. 18 |
| R520S, R520α | ||
| Engine Oil Capacity (124 mm oil pan depth) | 9.5 L (2.5 U.S.gals) | p. 18 |
| R420S | ||
| Tire Pressure (Front/Rear) | 2.6 bar (36.9 ± 1.4 psi) | p. 26 |
| R520S | ||
| Tire Pressure (Front/Rear) | 2.2 bar (31.2 ± 1.4 psi) | p. 26 |
| D1503-M, D1703-M, D1803-M, V2003-M, V2203-M, V2403-M, V2403-M-T, D1703-M-BG, V2003-M-BG, V2003-M-T-BG, V2203-M-BG, V2403-M-BG | ||
| Engine Compression Pressure (When Cranking) | 3.24 to 3.72 MPa | p. 257 |
Kubota R420–R520 Series Common Problems This Manual Covers
Weak or slow hydraulic lifting
Loaders in this class often lose lift power or raise slowly when pump wear, relief valve settings, or internal leakage creep in. The hydraulic troubleshooting covers weak lifting, slow lifting, and cylinder fall for any circuit.
Manual Section: Iv. Hydraulic System-Service p. 392Machine will not travel
A no drive condition in both forward and reverse points to the hydrostatic travel circuit or LST pump rather than the engine. The manual walks through diagnosing why the machine does not travel in either direction.
Manual Section: Iv. Hydraulic System-Service p. 392Negative brake will not release
These loaders use a negative (spring applied) brake, so a stuck parking or service brake can leave the machine locked. The brake and power train service section documents the negative brake releasing method and parking valve.
Manual Section: V. Brake System and Power Train-Service p. 590Hard starting or low compression
Worn valves, incorrect valve clearance, or low compression cause hard starting and rough running on the D1503 and V2203 series engines. The engine service section covers valve clearance, compression testing, and full teardown.
Manual Section: III. ENGINE-Service p. 136Battery discharges or starter fails
A battery that drains quickly or a starter that will not turn the engine is a common electrical complaint on these loaders. The electrical service section provides testing and troubleshooting for the charging and starting circuits.
Manual Section: Vi. Electrical System-Service p. 624Backhoe attachment drifts or is weak
On backhoe equipped machines, a boom or arm that drifts or lacks digging force usually traces to worn cylinders, pins, or hydraulic data out of spec. The backhoe service section gives hydraulic data and pin and bushing dimensions.
Manual Section: VII. BACKHOE-Service p. 696Frequently Asked Questions
Which Kubota models does this manual cover?
It covers the Kubota R420α, R520α, R420S, and R520S wheel loaders, including the interim Tier 4 and Stage III A emissions engine versions, under publication number 97899-62060.
How do I set the engine valve clearance?
The engine service section gives the valve clearance and compression specifications along with the adjustment and testing procedures for the D1503 and V2203 series engines fitted to these loaders. p. 136
Does it help troubleshoot hydraulic faults?
Yes. The hydraulic system service section includes structured troubleshooting for problems like weak lifting, slow lifting, cylinder fall, and a machine that will not travel, tied to the LST pump and circuit components. p. 392
How do I get the manual after purchase?
The manual is delivered as an instant PDF download after checkout, so you can access it right away and keep your own copy on hand for future repairs.
How quickly can I access this Kubota R420–R520 Series manual after buying?
Immediate download of the complete 820-page searchable workshop manual. Open it on any device: laptop at your desk or phone out in the field.
Am I able to print pages from this Kubota R420–R520 Series manual?
None at all. The PDF is DRM-free, so print whatever sections you need to take out to the shop. Standard letter or A4 paper works fine.
Are electrical wiring diagrams included in this Kubota R420–R520 Series manual?
Yes, they're included. This workshop manual provides complete wiring harness diagrams, electrical circuits, and connector pinouts.
Reviews
There are no reviews yet.