A slipping transmission or slow lift arms on your wheel loader is today's job, and this Komatsu WA450-3 shop manual PDF answers it with 854 pages of factory data (form CEBM003602) for both the standard machine and the -3MC. Hydraulic schematics trace oil from the pump through the main control valve to the lift and bucket cylinders, and the wiring diagrams at the back map the electrical circuits. Troubleshooting fills nearly a fifth of the book, working through engine, electrical, transmission controller and ECSS faults, while disassembly and assembly takes over a third, from the torque converter to the hydraulic cylinders. Set main relief to 210 +10/-3 kg/cm² at high idle with oil at 45 to 55 °C, then confirm clutch pressure holds 23 ± 2 kg/cm². Alone with the loader, there's nobody to ask. Bookmarked and text-searchable, the file is yours after one purchase, for as long as your loader runs.
What's Inside This Komatsu WA450-3, WA450-3MC Manual
| System | Pages | Key Topics |
|---|---|---|
| Foreword | 2-13 | Contents, Product Publications, Revised Edition Mark, Symbols |
| Safety | 14-15 | General Precautions, Preparations for Work, Precautions During Work |
| General | 16-43 | How to Read Shop Manual, Hoisting Instructions, Coating Materials, Standard Tightening Torque, Electric Wire Code, Conversion Tables |
| Structure and Function | 44-250 | Power Train, Transmission, Steering Valve, Brake Piping, Hydraulic Piping, Work Equipment, ECSS, Machine Monitor System |
| Testing and Adjusting | 251-310 | Standard Value Tables, Engine Speed, Intake Air Pressure, Valve Clearance, Stall Speed, Brake Performance, Load Meter |
| Troubleshooting | 311-467 | Troubleshooting Sequence, Engine System, Electrical System, Transmission Controller System, ECSS System |
| Disassembly and Assembly | 468-792 | Starting Motor, Radiator, Engine, Torque Converter, Transmission, Parking Brake, Main Control Valve, Hydraulic Cylinders |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Mounting bolt torque for turbine and case assembly to stator shaft and pump assembly | 30.9 ± 3.4 N•m (22.8 ± 25.1 lbf ft) | p. 511 |
| Mounting bolt torque for turbine (6) to case (7) | 30.9 ± 3.4 N•m (22.8 ± 25.1 lbf ft) | p. 511 |
| Slow blow fuse | 80 amp, 120 amp, 30 amp | p. 221 |
| Fuse | 10 amp | p. 221 |
| Clutch pressure | 23 ± 2 kg/cm² | p. 253 |
| Main control valve relief pressure | 210 +10/-3 kg/cm² | p. 255 |
| Specified dimension c | 3.8 ± 0.2 mm | p. 270 |
| Clearance between cam (3) and roller (4) | 0 to 0.5 mm | p. 297 |
| Dimension b (roller at notch at both ends of cam) | 0 to 1 mm | p. 297 |
| Voltage between E19-1 and chassis ground | 20 to 30 V | p. 396 |
| Engine Oil Capacity (Refill) | 38 L | p. 37 |
| Torque Converter/Transmission Oil Capacity (Refill) | 60 L | p. 37 |
Komatsu WA450-3, WA450-3MC Common Problems This Manual Covers
Komatsu WA450-3 wheel loader engine starting performance poor, cranking a long time before it fires
Measure voltage between alternator terminal B and terminal E with the engine at low idle following page 345, and confirm 26 to 30 V. A low reading puts the alternator circuit under suspicion. Verify low idle sits at 765 ± 15 rpm per page 252 before you trust the reading.
Manual Section: Engine System (S Mode) p. 345Transmission controller system shows a modulation valve solenoid or F/R solenoid circuit fault
Disconnect and measure resistance across solenoid connector T12 pins 1 and 2 following page 420; spec is 12 to 15 Ω. Check T01, T02 and T03 pins 1 and 2 against 46 to 58 Ω on pages 422 to 424. Then test voltage from L29-3 to chassis on page 421 for max 1 V.
Manual Section: Transmission Controller System (A Mode) p. 420Loader does not move or travels weakly with engine running and directional lever engaged
Measure transmission clutch pressure following page 253 and compare against 23 ± 2 kg/cm². Check the directional lever and travel speed sensor circuits in the Transmission Controller System (A Mode) section before splitting any cases. After a drain, refill the torque converter and transmission with 60 L as listed on page 37.
Manual Section: Testing and Adjusting p. 253Boom raises slowly or bucket cylinders move weakly under load at the pile
Warm the hydraulic oil to 45 to 55 °C, hold the engine at high idle, and measure main control valve relief pressure following page 255. Spec is 210 +10/-3 kg/cm². If pressure reads low, check the relief first. If it is on spec, work the boom and bucket items in the Hydraulic and Mechanical System (T Mode) section.
Manual Section: Testing and Adjusting p. 255Steering responds slowly or turns heavy when working the loader at engine high idle
Bring the hydraulic oil to 45 to 55 °C and run the engine at high idle. Measure steering valve relief pressure following page 254 and compare against 210 +5/-4 kg/cm². If pressure is on spec, work through the steering items in the Hydraulic and Mechanical System (T Mode) section before replacing parts.
Manual Section: Testing and Adjusting p. 254Brakes feel weak or slow to respond during repeated stops in load and carry cycles
Measure accumulator charging cut out pressure following page 254. Spec is 100 +10/0 kg/cm², read at the point where oil pressure climbs and then starts to drop. Check brake performance per the Testing and Adjusting section, then work the brake items in the Hydraulic and Mechanical System (T Mode) section.
Manual Section: Testing and Adjusting p. 254Frequently Asked Questions
How do I reset or clear Komatsu WA450-3 fault codes?
To clear failure codes, press the rear working lamp switch for at least two seconds while in the trouble data display mode. Note that failure codes for problems currently occurring cannot be cleared. p. 188
How do I retrieve diagnostic codes on a Komatsu WA450-3?
To enter the trouble data display mode, ensure the engine is stopped and the start switch is turned ON. Press the 2nd switch from the top on the left side of the main monitor and the front working lamp switch simultaneously for at least five seconds. p. 188
Why does the WA450-3 have excessive shock when starting or shifting gears?
Excessive shock during starting or shifting is often caused by a defective modulation valve, a defective check valve in the directional valve, or a defective operation of the directional spool. Check the transmission control valve and accumulator valve for these issues. p. 441
Why is there excessive time lag when starting or shifting gears?
Excessive time lag is typically caused by a clogged orifice, leakage due to wear of the piston or spool, or a defective check valve in the directional valve. These issues affect the transmission control valve and accumulator valve. p. 442
What is the torque for the torque converter case mounting bolts on the Komatsu WA450-3?
Tighten the torque converter case mounting bolts to 112.8 ± 9.8 N•m (83.2 ± 7.2 lbf ft). p. 524
What do I get after purchasing this Komatsu WA450-3 manual?
This is a 854-page searchable PDF ready for immediate download. Works on any device, so pull it up on your phone while you're under the hood. No shipping, no waiting.
Is this Komatsu WA450-3 Shop Manual printable?
Yes. It prints from any PDF reader, so run off the pages you need for your own repair work.
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