Komatsu D68E-1, D68E-1A, D68P-1, D68P-1A Bulldozer Workshop Manual (P/N SEBMU1440102)

Komatsu shop manual SEBMU1440102 covers the D68E-1, D68E-1A, D68P-1, and D68P-1A bulldozers, including the Brazilian configurations. It documents component operation, testing, adjustment, and workshop repair for the covered machines.

• Engine and fuel system: Engine and cylinder-head removal and installation, valve-clearance checks, compression testing, injection-pump timing, and nozzle-holder replacement.

• Cooling system: Water-pump, radiator, torque-converter cooler, and radiator-guard removal and installation, with engine and steering oil-cooler service procedures.

• TORQFLOW power train: Torque-converter and planetary-transmission disassembly and assembly, control-valve service, clutch-piston checks, and pressure-based troubleshooting.

• Steering and final drive: Steering-clutch overhaul, brake and linkage adjustment, bevel-gear setup, final-drive teardown, and component inspection standards.

• Undercarriage: Track-frame and recoil-spring service, idler and roller replacement, master-link track separation and connection, and wear measurements.

• Blade hydraulics: Pump and control-valve replacement, blade lift and tilt cylinder rebuilding, air bleeding, and diagnosis of weak lift or excessive drift.

• Electrical references: Wiring and circuit diagrams, wire-size and color-code tables, and starter-motor and alternator removal and installation.

Written for service personnel performing workshop repairs, the manual includes work requiring presses, lifting equipment, and Komatsu service tools.

Engine Testing and Assembly Work

The injection-timing section distinguishes match-mark alignment for an unrepaired pump returned to the same engine from the delivery-check method for a replacement or repaired pump. Compression testing specifies the gauge and adapter used for the measurement.

Engine mounting drawings explain shim-based alignment with the transmission. Cylinder-head coverage concerns removal and installation of the assembly; complete internal 6D125-1 engine overhaul requires the separate engine volume.

General reference pages provide component weights, oil and coolant capacities, and standard tightening torques. Assembly sections supply component-specific exceptions.

TORQFLOW Diagnosis, Steering, and Final Drive

Diagnostic tables address torque-converter overheating, poor drawbar pull, delayed shifts, and steering faults. Used with the pressure-measuring-point diagrams, they help narrow down hydraulic-control and clutch problems before major components are dismantled.

The No. 3 clutch section explains how its ball check valve releases trapped oil so the clutch can disengage during a gear change. Rebuild instructions cover clutch-piston operation checks and seal-ring orientation; bevel-gear installation adds tooth-contact checks and bearing-preload adjustment.

Track Service and Blade Hydraulics

Track documentation distinguishes master-pin and master-link designs, with separate wear standards and bolt-tightening requirements. Recoil-spring service specifies compressor 791-685-8002, while roller and idler sections explain measurement methods and repair limits.

Hydraulic coverage includes the PAR112 pump, two-spool blade control valve, and cylinder rebuilding. Separate circuit diagrams show straight-tiltdozer configurations with and without a ripper; DRP060 coverage includes ripper construction, hydraulic components, and maintenance standards.

Cylinder assembly notes cover wear-ring installation because direct contact between the steel piston and cylinder can scratch both surfaces.

Always fully depressurize hydraulic circuits, consult the full OEM procedures, and follow the specified precautions for heavy lifting and loaded recoil springs.

Wiring and System Diagrams

The electrical wiring and circuit diagrams identify the starting safety circuit, charging system, lighting, gauges, and back-up alarm. Detailed electrical component information is covered in the separately referenced electrical-system shop manual.

Other visual references include PTO gear-train views, the power train hydraulic system schematic, the transmission lubrication chart, and blade hydraulic control diagrams.

A Sample of TORQFLOW and Bevel Gear Specifications

These examples represent a small selection of the power-train data in the manual.

The FAL040 TORQFLOW pump is listed at 73.7 L/min at 1,850 rpm. Bevel-gear installation specifies 0.25–0.33 mm backlash and bearing preload measured as 1.5–2.0 kgm turning torque with the pinion engaged.

PDF Reading, Diagrams, and Page Count

Text search and wiring detail: Only the cover has searchable text, and there are no embedded PDF bookmarks. Small connector numbers and wire codes in the electrical circuit diagram require zooming.

Supplied as one printable 409-page PDF. The total already includes the cover, two revision-list pages, and 35 blank pages.