Komatsu WA320-3 Avance Wheel Loader 2003–2006 Shop Manual Set (P/N SEBM006006)

The volumes cover different serial-number configurations. Match the machine to the appropriate volume before selecting specifications, test procedures, or component repair instructions.

Engine-overhaul scope: The 50001-up chassis volume covers engine-related testing, external-component repair, cylinder-head work, and engine removal and installation. It directs detailed S6D108 engine work to the separate 108 Series Engine Shop Manual, which is not included.

H-series electrical coverage: The separate foldout sheets referenced in the Wiring Diagrams section and part of the air-conditioning section are not included. Component tables and individual system circuit diagrams remain available; the 50001-up electrical drawings do not replace the missing H-series sheets.

PDF Search, Bookmarks, and Page Breakdown

Text search and circuit detail: The 50001-up PDF has no text search. The H-series PDF supports text search in its text sections, although several circuit drawings have image-based labels. Both PDFs have embedded bookmarks for chapters and component sections. Small circuit labels require zooming, particularly on the large-format 50001-up electrical sheets.

The 1,807-page ZIP download contains two printable PDFs. This total includes 23 preliminary pages in the 50001-up volume and eight in the H-series volume, together with internal separator and blank pages. The H-series total also includes 26 foldout-placeholder pages.

Drivetrain, Hydraulic, and Electrical Repair Coverage

The following topics are selected examples from the manuals rather than a complete contents list. Additional subjects include cab and counterweight removal, along with air-conditioning component service.

• Transmission repair: Step-by-step procedures for torque converter and transmission removal, clutch-pack disassembly and assembly, control-valve repair, and post-assembly clutch checks.

• Axles and articulation: Front and rear axle removal, torque-proportioning differential and axle-housing overhaul, final-drive inspection, and center-hinge-pin replacement.

• Hydraulics and steering: Hydraulic/steering pump removal, main-control-valve and cylinder overhaul, steering-valve service, pressure testing, and bucket-positioner and boom-kick-out adjustment.

• Brakes and accumulators: Brake-pressure and disc-wear checks, brake-system bleeding, parking-brake inspection, and accumulator testing and adjustment.

• Engine-related service: Valve-clearance checks, compression and blow-by testing, injection-timing checks, turbocharger and nozzle-holder work, cooling-component service, and cylinder-head procedures.

• Electrical diagnosis: Engine, monitor, and transmission-controller troubleshooting, connector pin arrangements, wiring-continuity checks, sensor tests, and individual control-circuit diagrams.

The manuals are written for service personnel performing workshop repairs, including work that requires Komatsu special tools, pressure-test equipment, and lifting equipment.

Transmission Operation and Internal Repair

The drivetrain chapters explain the TCA32-8A three-element, single-stage, single-phase torque converter and the directional and speed-clutch circuits. The transmission control valve, pilot reducing valve, main relief valve, priority valve, quick-return valve, and accumulator circuits are described in their operating context.

Flow descriptions show how clutch and converter circuits respond during gear selection and pressure modulation, which is useful when a repair problem is hydraulic rather than mechanical. The repair sections add internal assembly instructions, inspection standards, drive-shaft work, and wet-disc parking-brake service.

Transmission assembly notes address input-shaft spline alignment and seal-ring damage, while the parking-brake procedures identify piston-seal direction, twisting, and shaft contact at the cover oil seal.

Hydraulic Variants, Steering, and Work Equipment

The combined hydraulic/steering/switch/PPC pump is identified as SAL(3)71+(3)32+(3)32+(1)20. Steering coverage follows the priority valve, orbit-roll steering valve, cushion valve, steering cylinders, and emergency-steering functions.

Serial-specific sections distinguish accumulator charge valves and work-equipment circuits, along with the H-series main-control-valve versions. Pressure-test procedures are supported by hydraulic-drift limits, cycle-time specifications, PPC checks, and work-equipment adjustment data.

The H-series lubricant information distinguishes standard TPD axles from versions with multi-disc limited-slip differentials. This distinction matters when selecting axle lubricant and matching the repair information to the installed axle.

Center-hinge bearings and spacers are clearance-matched sets; mixing the combinations or omitting a spacer can compromise bearing fit and risk bearing damage.

Engine Testing and Cooling-System Work

Engine-related chassis procedures extend beyond removal and installation. The manuals provide compression, blow-by, boost-pressure, oil-pressure, and injection-timing checks, with the applicable engine test specifications.

Cooling-system work includes radiator, water-pump, and thermostat procedures. The 50001-up volume separates water-pump removal and installation for the earlier and later serial-number configurations.

Circuit Drawings and Fault Isolation

Representative drawings include the Transmission Hydraulic Circuit Diagram, Brake Hydraulic Circuit Diagram, and Work Equipment Hydraulic Circuit Diagram. Electrical references include the Kick-Down Electric Circuit Diagram and Connector Pin Arrangement Diagram.

Troubleshooting sections connect symptoms with checks for the engine, main monitor, and transmission controller. Coverage also includes auto-shift operation, transmission cut-off, electric parking-brake control, E.C.S.S., speedometer/main-monitor adjustment, and related sensors.

Workshop Tools and Service Precautions

Tool references include the 799-101-5002 hydraulic tester, 793-520-1803 brake test kit, and 793-463-1100 boom-drop prevention stopper. Transmission clutch-piston seal holders are identified individually: 793-415-1160 for forward/reverse, 793-415-1170 for first/third, and 793-415-1130 for second/fourth.

These repair procedures involve stored hydraulic and brake pressure, heavy driveline components, and raised work equipment. Follow the manual’s pressure-release, blocking, lifting, and electrical-isolation precautions before beginning structural or hydraulic repair work.

Examples of Fluid-Capacity and Assembly Data

The H-series lubricant table lists a 42 L transmission capacity with a 40 L top-up quantity, and 165 L for the hydraulic system with a 116 L top-up quantity. Its air-conditioning entries specify R134a at 1,500 g and PAG oil at 150 cm³.

The hydraulic pump specification lists delivery as 165+77+77+49 L/min. Component-specific assembly data includes a transmission coupling mounting-bolt torque of 549 ± 59 Nm, alongside the associated seal-protection notes.