Komatsu-Cummins N-855 Series Diesel Engine Shop Manual – N-855-C, NT-855-C & NTA-855-C PDF Repair Guide

Description

Komatsu-Cummins N-855 Series Diesel Engine Shop Manual

This is the complete Komatsu-Cummins N-855 Series Diesel Engine Shop Manual – the same technical reference used in Komatsu service workshops for the N-855-C, NT-855-C and NTA-855-C inline six-cylinder diesel engines. It covers engine serial number 26100001 and up, and applies to a wide range of Komatsu machines including the PC300-1, PC300-2, PC300LC-1, PC300LC-2, PC400-1, PC400LC-1, D80A-18, D80E-18, D80F-18, D85A-18, D85E-18, D85P-18, D95S-2, W170-2, W180-1, HD320-2, HD320-3, WS16S-2 and WS23-1.

Whether you are rebuilding a PT fuel pump, setting injector and valve clearances, chasing a low-oil-pressure complaint, or pulling a cylinder head on a D85 dozer, this N-855-C / NT-855-C / NTA-855-C shop manual gives you the Komatsu procedure, the Komatsu specification and the Komatsu judgement standard for the job in front of you.

File Details

• Manual type: Diesel Engine Shop Manual
• Brand: Komatsu / Cummins
• Engine series: N-855 Series
• Engine models covered: N-855-C, NT-855-C, NTA-855-C
• Language: English
• Page count: 279 pages
• File format: PDF (instant download)

Chapters Covered

• 01 General
• 11 Structure and Function
• 12 Testing and Adjusting
• 13 Disassembly and Assembly
• 14 Maintenance Standard
• 15 Repair and Replacement
• 19 Others

01 General

Opens with the engine specification tables that cover dimensions, displacement, firing order, performance figures, fuel pump and governor type, lubricating oil and cooling water capacities, alternator, starting motor and battery ratings for each of the N-855-C, NT-855-C and NTA-855-C variants. Includes labelled engine photographs and side/front/rear dimension drawings showing crankshaft centre, flywheel housing rear face and cylinder centre references. The general section also contains the safety, disassembly/reassembly, detergent, nut-and-bolt, locking-device, press-fitting, measuring-tool and hoisting instructions used throughout the rest of the book, plus the standard tightening torques, split-flange bolt torques, flared nut torques and the coating materials table.

11 Structure and Function

Explains how each system works on the N-855 Series engine before you touch it. Intake and exhaust layouts are shown for the naturally aspirated, turbocharged and turbocharged-aftercooled versions. Turbocharger cutaways are given for both the Cummins ST-50 and the Komatsu KTR-130, with specifications such as continuous rotation, maximum charging rate, inlet temperature limit and lubrication method. The engine body chapter covers the cylinder head, valve arrangement, cylinder block, cylinder liner and clevis seal, main circulation, timing gear train, camshaft, cam follower and push rod, injection and valve timing diagrams, flywheel and flywheel housing. Lubrication system is covered through the oil pump, oil filter, full-flow and by-pass filters, oil cooler and regulator valve. The fuel system section covers the PT fuel pump, PT pump drive, injectors, fuel filter, water separator and aneroid control valve, while the cooling system chapter covers the water pump, fan drive, tension pulley, thermostat and corrosion resistor. Accessory and electrical chapters cover the air compressor, alternator, starting motor and electrical intake air heater.

12 Testing and Adjusting

This is where most day-to-day diagnostic work starts. Procedures are given for measuring compression pressure, blow-by pressure, oil consumption and fuel pressure. Injector and valve clearance testing and adjusting are laid out step by step with the firing order 1-5-3-6-2-4, torque wrench settings for the injector adjustment screw, and the cold/warm clearance values that change at engine number 26155792. The PT pump calibration data and PT fuel pump parts specification tables list idle plunger dimensions and Komatsu/Cummins part numbers, governor springs with their colour codes, free length, spring rate, wire diameter and coil count, plus plunger, torque spring, AFC spring and shim thickness data. Injector delivery volume, pressure, number of holes and orifice sizes are also tabulated. Run-in standard, performance test criteria, the testing and adjusting tool list, testing and adjusting data, and a troubleshooting section complete the chapter.

13 Disassembly and Assembly

Detailed removal and installation procedures for the engine and its major sub-assemblies. Covers the rocker arm housing, cylinder head, valve system, cylinder block, main bearing caps, piston and connecting rod assembly, crankshaft, camshaft, timing gears, flywheel housing, PTO and hydraulic pump drive systems, oil pump, water pump, PT fuel pump drive, injectors, turbocharger and after-cooler. Each procedure is supported by exploded-view illustrations and the correct bolt-tightening sequences so bearings, seals and gaskets seat correctly the first time.

14 Maintenance Standard

Gives the judgement standards for inspecting disassembled parts – the values you need when deciding whether a component can be reused, repaired or must be replaced. Standard size, tolerance, repair limit, standard clearance and clearance limit are all defined and applied to the engine’s wearing components.

15 Repair and Replacement

Covers repair and replacement procedures for components that fall outside the maintenance standard, along with the service tools required for the work.

Engine Specifications You Can Work From

The general chapter opens with the hard numbers for every variant. All three engines share the same 6-cylinder, 139.7 mm x 152.4 mm bore and stroke, 14,010 cc displacement and 1-5-3-6-2-4 firing order. Output ratings differ by application – for example 180 HP / 1,850 rpm for the PC300-1 and PC300LC-1, 220 HP / 1,800 rpm for the D80A,E-18 and D85A,E,P-18, 260 HP / 1,950 rpm for the D80F-18, 405 HP / 2,300 rpm for the HD320-2 and HD320-3, and 364 HP / 2,100 rpm for the WS23-1. High and low idling speeds, minimum fuel consumption ratio, dry weight, lubricating oil capacity, cooling water capacity, alternator output, starting motor rating and battery configuration are listed alongside each machine.

Because the N-855-C, NT-855-C and NTA-855-C differ in turbocharging and after-cooling, the intake and exhaust chapters show the correct plumbing for each version. The NTA-855-C units add an after-cooler between the turbocharger and the intake manifold, with its own core, cover and housing, and the manual documents the water and air routing for that assembly.

Why This Manual Matters for Your N-855 Series Engine

These engines are still working hard in excavators, dozers, wheel loaders and haul trucks. When one comes into the shop, guessing at torque values, injector settings or fuel pressure is expensive. The N-855 Series shop manual gives you the manufacturer’s numbers: the injector adjustment screw torque, the locknut torque, the valve clearance change point at engine number 26155792, the PT pump idle plunger dimension, the governor spring colour code and rate, the regulator valve setting of 4.4 ± 0.4 kg/cm², the oil filter safety valve setting of 3.15 ± 0.35 kg/cm², and the turbocharger limits for both the Cummins ST-50 and the Komatsu KTR-130.

It also gives you the procedures that keep the job safe and correct – how to rotate the crankshaft to the 1.6VS mark before setting injectors and valves, how to remove and refit the injector with the correct puller, how to block up rocker housing vent holes for a blow-by test, and how to reconnect high-pressure hoses and split flanges without twisting or crimping them.

IMAGES PREVIEW

Instant PDF Delivery – No Shipping, No Waiting

The Komatsu-Cummins N-855 Series Diesel Engine Shop Manual is delivered as a downloadable PDF the moment your order is complete. No shipping charges, no waiting for a parcel, no risk of a damaged or missing book. Open it on a laptop, tablet or phone in the workshop, print the pages you need for the job at hand, and keep the full 279-page reference on file for every N-855-C, NT-855-C and NTA-855-C engine that comes through your bay. If you service Komatsu equipment, this manual belongs on your device.