2001 and Up Komatsu D39EX-21 & D39PX-21 Bulldozer Shop Manual PDF (P/N SEBM023810)

Komatsu shop manual SEBM023810, printed in Japan in November 2007, covers the 2001 and newer D39EX-21 and D39PX-21 bulldozers, both from serial 1001 and up.

• Engine service: Fuel-injection timing, compression and oil-pressure tests, cylinder-head removal and installation, and front and rear crankshaft-seal replacement.

• HST and final drives: Pressure testing, travel-deviation adjustment, pump removal and air bleeding, and planetary final-drive disassembly and assembly.

• Blade hydraulics: CLSS operating diagrams, PPC output-pressure checks, control-valve service, and lift, tilt, and angle cylinder rebuilding.

• Undercarriage: Track-tension adjustment, recoil-spring and idler service, track and carrier roller rebuilding, and shoe and sprocket inspection limits.

• Electrical diagnosis: Starting, gearshift, parking-brake, machine-monitor, and air-conditioning troubleshooting, supported by connector charts and circuit diagrams.

• Workshop references: Tightening-torque tables, lubricant capacities, maintenance standards, and special-tool lists and sketches.

This manual suits technicians familiar with hydraulic pressure testing and equipped for component lifting and press work.

HST, Steering and Blade Hydraulics

The power train section explains the HPV63 + 63 pump, KMV105 variable bent-axis motors, charge pump, and steering and brake controls. Section views show the 3rd-speed valve, shuttle valve, and pressure-relief circuits.

The HST Hydraulic Equipment Arrangement Diagram and Hydraulic Circuit Diagram distinguish early and later control layouts. Matching these drawings to the machine's serial range helps technicians select the correct brake/inching and steering circuits before diagnosing a travel problem.

The Closed-center Load Sensing System (CLSS) section explains unload-valve and pressure-compensation operation. Cylinder-leakage tests help distinguish an actuator leak from a control-valve fault.

Valve service limits: Komatsu warns against dismantling the later steering/directional PPC valve because its output-pressure and operating-effort characteristics then require readjustment. The main-control-valve procedures also restrict internal disassembly of the safety, suction, and main relief valve assemblies.

Engine and Cooling-System Repair

Engine diagnosis includes blow-by and boost-pressure measurements, plus symptom charts for hard starting, smoke, overheating, and low oil pressure. Engine removal and installation are documented alongside injection-pump and cylinder-head service.

Engine coverage: This chassis volume contains the engine procedures listed above; detailed internal engine work is referred to the separate 102-2 Series Engine Shop Manual, which is not included.

Cooling-system procedures cover removal and assembly of the radiator, oil cooler, and charge-air cooler.

Rear crankshaft-seal removal carries a specific warning about tool damage to the flywheel seal seat and crankshaft wear ring.

Final Drives, Undercarriage and Cab Work

Final-drive rebuilding covers both planetary stages, bearings, floating seals, and bearing-preload checks. The hub-nut procedure warns that incomplete bearing seating can damage the floating-seal contact faces.

Idler and roller procedures address bushing fits, seal installation, and roller leakage checks. Recoil-spring work specifies compressor 791-685-8006 and hydraulic tooling, while cab-frame removal identifies serial-specific linkage and hose differences.

Follow the manual's blocking, lifting, and hydraulic-pressure precautions, particularly when handling the recoil spring and suspended assemblies.

Electrical Fault Tracing

Troubleshooting is organized into E-mode electrical, H-mode hydraulic/mechanical, M-mode monitor, and S-mode engine sections. Electrical flowcharts link test results to causes and remedies; monitor charts distinguish gauge, warning-lamp, and travel-speed-display faults.

The Connector Arrangement Diagram and Connection Table for Connector Pin Numbers identify harness locations and test connections. The Electrical Circuit Diagram and separate Electrical Circuit Diagram for Air Conditioner support tracing machine and cab circuits.

Selected Valve-Clearance and Track-Tension Values

These are a few of the engine and undercarriage adjustment values included in the manual. At normal temperature, SAA4D102E-2 valve clearance is 0.25 mm at the intake valves and 0.51 mm at the exhaust valves.

For both models, the track-tension check specifies a 20–30 mm gap between a straight bar spanning the front idler and carrier roller and the grouser at the midpoint. This measurement applies on level ground after forward travel and a stop without brake application.

Text Search, Bookmarks and PDF Contents

Navigation and diagram detail: Text search works across the narrative sections, and embedded PDF bookmarks provide access to chapters and individual procedures. Some diagnostic-chart content and schematic labels are not searchable. Small wiring and connector markings require zooming.

Supplied as one printable 464-page PDF in English. The total already includes one cover page, three revision-list pages, and six blank pages.