Komatsu D21A-8E0, D21P-8E0 Bulldozer Shop Manual 2005–2007 (P/N SEN03320-04)

Komatsu shop manual P/N SEN03320-04 covers the 2005–2007 D21A-8E0 and D21P-8E0 bulldozers, serial numbers 90001 and up for each model. It covers chassis repair, engine testing and adjustment, and the steel- and rubber-crawler specifications.

PDF Search, Bookmarks and Drawing Detail

Text access and circuit labels: Main text is searchable, and embedded bookmarks link to sections and procedures. Many labels within drawings are not text-searchable. Small wire codes and connector numbers on the large circuit sheets require zooming.

One printable, 462-page PDF contains 460 section pages plus the overall cover and one unnumbered blank page. Section title pages, imprint pages and three blank diagram backs are already included in that total.

Hydroshift, Steering and PAT Dozer Service

This selection of covered work highlights the main repair areas; other topics include fan-belt replacement and fuel-circuit air bleeding.

• Engine testing: Valve-clearance adjustment, compression and oil-pressure measurements, fuel-injection timing adjustment, and fuel-control linkage checks.

• Hydroshift transmission: Modulating and inching pressure tests, plus step-by-step disassembly and reassembly of the illustrated F2-R2 transmission assembly.

• Steering and final drives: Steering-clutch overhaul, band-brake adjustment, bevel-gear setup, final-drive removal and repair, and first-pinion service.

• PAT hydraulics: Main-relief pressure testing and adjustment, steering and cylinder bleeding, and control-valve and hydraulic-cylinder assembly details.

• Undercarriage: Steel- and rubber-crawler wear standards, recoil-spring removal and repair, and track master-pin removal and installation.

• Fault diagnosis: E-mode electrical, H-mode hydraulic/mechanical and S-mode engine troubleshooting charts for starting, charging, travel, steering and blade problems.

• Circuit drawings: Separate F2-R2 and F3-R3 power train hydraulic diagrams, the PAT work equipment hydraulic diagram, and main and cab/air-conditioner electrical diagrams.

This manual is suited to mechanics familiar with crawler-dozer service and equipped for hydraulic testing, precision measurements and spring-compressor work.

Engine Service and Injection-Pump Coverage

Engine and fuel-injection-pump removal and installation are included, along with radiator-guard removal. Internal engine repair requires the separate engine-volume manual, which is not included in this PDF.

Fuel-control linkage and engine-stop solenoid operation are explained, including machines with a decelerator pedal. The MP-type injection-pump adjustment uses the pump’s recorded injection angle rather than a conventional timing measurement.

The pump-removal instructions warn that disturbing the drive-gear-to-flange relationship makes subsequent fuel-injection timing adjustment difficult.

Transmission, Steering and Final-Drive Repair

Planetary-gear operation is paired with clutch-disc, plate and spring wear limits. F2-R2 uses four clutches; F3-R3 uses five. The illustrated transmission rebuild follows the F2-R2 layout; F3-R3 has separate structure, maintenance-standard and hydraulic-circuit information.

Bevel-gear installation includes bearing preload, backlash and tooth-contact adjustment. Final-drive procedures add bearing-preload shimming and flange runout checks. The transfer-case instructions identify bearing-cage damage as a risk when forcing screws are used for the wrong removal operation.

The H-7 troubleshooting entry links a falling transmission oil level and rising bevel-gear-case level to the transmission output-shaft O-ring or oil seal. That connection helps focus leak diagnosis before dismantling assemblies.

Hydraulic Components and PAT Blade

Separate pump sections document the power train/steering pump and work equipment pump, with discharge-test conditions and repair limits. Hydraulic tank and cartridge-filter construction, spool operation, and relief and suction valves are explained.

Lift, tilt and angle cylinder data include bore, stroke and pin distances. The control-valve and cylinder repair sections concentrate on assembly precautions, seal orientation and component-specific tightening data.

Track Components and Workshop References

Steel-track and integrated-rubber-crawler sections provide wear criteria for the respective track components. Idler, track-roller and carrier-roller tables distinguish standard dimensions from repair limits.

The specification dimension drawing and component weight tables support transport and lifting preparation, including the main frame, radiator and undercarriage assemblies. Standard torque tables cover metric fasteners, split-flange bolts and O-ring boss piping joints.

Follow the manual’s load-support, hydraulic-pressure and stored-spring precautions when lifting components or servicing the track tensioner.

Electrical Fault Tracing and KOMTRAX

Connector views, pin-connection tables and T-branch adapter listings support wiring-harness checks. Electrical troubleshooting covers starting interlocks, engine-stop control, charging faults and sensor inputs.

KOMTRAX TC310 documentation includes terminal connections, diagnostic indicators and fault checks, together with terminal removal and installation.

Examples of Valve and Cylinder Clearances

The engine standard-value table specifies a cold clearance of 0.2 ± 0.05 mm for both intake and exhaust valves on the 4D94LE-2.

For PAT lift, tilt and angle cylinders, standard piston-rod-to-bushing clearance is 0.086–0.274 mm. The table gives a 0.574 mm clearance limit and specifies bushing replacement as the remedy.