Komatsu N855 Series Diesel Engine Shop Manual

Komatsu N855 Series Diesel Engine Technical Documentation

• Covers the Komatsu-Cummins N-855-C, NT-855-C, and NTA-855-C diesel engine series as utilized in PC300-1, HD320-2, and D85A-18 machine platforms
• Official Komatsu publication SEBE6710A03, printed in Japan, dated September 1984
• Includes 12 assembly-view schematics, 9 detailed performance curves, and 4 comprehensive torque specification tables
• File link appears in your order confirmation straight away
• OCR text layer lets you jump to a torque spec by keyword
• Suitable for printing individual sections for shop-floor use
• Stored against your account so you can retrieve it after a hard-drive loss
• This 1984 edition serves as the foundational technical reference for the N-855 series, documenting the transition from earlier N-855 configurations to the turbocharged and after-cooled NTA variants

Internal System Documentation

The Komatsu N855 series service manual provides detailed technical descriptions for major engine subsystems including intake, exhaust, fuel, and lubrication systems. It outlines the structure of the cylinder block, crankshaft, and timing gear assemblies. This publication documents the operational function of turbochargers, after-coolers, and the specific Cummins PT fuel pump and governor arrangements for various machine applications. Reference data is included for troubleshooting symptoms like reduced power, oil leaks, and abnormal hydraulic pressure, providing clarity for maintenance work.

Engine Specification Highlights

Specifications are provided for multiple variants including N-855-C, NT-855-C, and NTA-855-C models across industrial and heavy equipment applications. The cylinder head intake valve clearance for Engine No. 26100001–26155791 is documented at 0.41 mm in the cold state. Standard tightening torque for a 12 mm thread diameter bolt is specified at 112 ± 9.8 Nm. The Komatsu N855 engine dry weight varies by specific model configuration between 1,450 kg and 1,750 kg. Understanding parts documentation for industrial diesel engines provides further guidance for identifying specific components across different serial number ranges.

Note: This page is a contents overview for the manual. It does not provide repair or diagnostic instructions. This official 279-page Komatsu service manual details the shop-grade maintenance and assembly specifications for the N855 series diesel engine, providing technical data for the 1984-era generation of heavy-duty industrial machinery.