Engine Family:
Hino W04D series
Engine Models Covered:
W04DH, W04DK
Engine Type:
Inline four-cylinder, overhead valve diesel
Displacement:
4.0 L class (W04D family)
Production Years Covered:
As documented in the parts manual for the W04DH and W04DK variants
Document Scope:
Component and part number identification for service, overhaul and replacement
Primary Users:
Diesel technicians, fleet workshops, and experienced DIY owners servicing Hino W04D engines
Skill Level:
Professional and advanced DIY
Use Case:
Part lookup, component identification, overhaul planning, and parts ordering
Exploded Diagrams:
Illustrated assemblies showing component order and part relationships
Part Number Reference:
Hino part numbers listed against each illustrated component
Assembly Coverage:
Engine and related subassemblies documented for W04DH and W04DK
Cylinder Block and Crankcase:
Block, main bearing caps, and crankcase component identification
Cylinder Head:
Head casting, valve train, and related components
Pistons and Connecting Rods:
Piston, rings, pin, and connecting rod assemblies
Crankshaft and Bearings:
Crankshaft, main and connecting rod bearing identification
Camshaft and Timing:
Camshaft, timing gears, and drive components
Fuel Injection System:
Injection pump, injectors, and fuel lines by part number
Fuel Supply:
Feed pump, filter head, and fuel piping components
Air Intake:
Intake manifold and related air path parts
Exhaust:
Exhaust manifold and associated fasteners
Lubrication System:
Oil pump, oil filter assembly, and oil pan components
Cooling System:
Water pump, thermostat housing, and cooling circuit parts
Electrical and Accessories
Starting System:
Starter motor mounting and related components
Charging System:
Alternator mounting and drive components
Gaskets and Seals:
Gasket sets, oil seals, and sealing components
Fasteners:
Bolts, studs, nuts, and washers by assembly
Illustration Style:
Exploded views with indexed part callouts
Part Number Format:
Hino OEM part numbers with quantity where shown
Application Data:
Variant applicability for W04DH and W04DK
File Format:
PDF (searchable, bookmarked, zoomable)
Compatibility:
Windows, macOS, Linux, iOS, and Android — any device with a PDF reader
Requirements:
A PDF reader application (e.g. Adobe Acrobat Reader, free)
Searchability:
Fully text searchable for fast lookup of any topic
Print Quality:
High-resolution digital pages, printable at full clarity
Binding Type:
N/A — digital download, no physical binding
Paper Type:
N/A — digital download, no physical paper
Length:
N/A - not specified in source data
Width:
N/A - not specified in source data
Height:
N/A - not specified in source data
Dry Weight:
N/A - not specified in source data
Wheelbase:
N/A - engine manual; refer to vehicle specifications
Curb Weight:
N/A - engine manual; refer to vehicle specifications
Fuel System Handling:
High-pressure lines and diesel fuel require controlled release and safe handling
Lifting Points:
Use rated lifting equipment on the block and head per workshop practice
Torque Compliance:
Fasteners must be tightened to the specified torque in the correct sequence
Component Replacement:
Use OEM-specified parts to maintain sealing and structural integrity
Fuel Delivery:
Mechanical injection system with serviceable pump and injectors
Governor:
Mechanical governing per engine variant
Cold Start:
Glow or intake heating as fitted to the application
Diagnostics:
Mechanical system; diagnosis by inspection, pressure, and timing checks
Oil Change Interval:
N/A - follow the vehicle manufacturer's schedule for the application
Oil Specification:
N/A - consult the vehicle operator manual for the required grade
Coolant:
N/A - consult the vehicle operator manual for the required specification
Fuel Filter:
Replace at the interval specified for the application
Valve Clearance:
Check and adjust cold per the engine service specification
Injectors:
Wear with fuel quality and hours; test and replace as needed
Fuel and Oil Seals:
Replace during overhaul and at every disassembly
Gaskets:
Replace head, pan, and cover gaskets on reassembly
Belts and Hoses:
Inspect for cracking and replace at the manufacturer's interval
