Mitsubishi S6S User manual

Service Manual
99709-56120
For use with FD40K, FD40KL, FD45K, FD50K,
FD60, FD70, Chassis Service Manual.
S6S Diesel Engine
28620-up

FOREWORD
This service manual covers S6S Diesel Engine of Mitsubishi Forklift Trucks and gives detailed
maintenance and repair information. The instructions are grouped by systems to serve the
convenience of your ready reference.
Long productive life of your forklift trucks depends to a great extent on correct servicing – the
servicing consistent with what you will learn from this service manual. We hope you read the
respective sections of this manual carefully and know all the components you will work on
before attempting any work.
All descriptions, illustration, specifications, and serial numbers in this manual are effective as
of the printing date of this manual. Mitsubishi reserves the right to change specifications or
design without notice and without incurring obligation.
Pub. No. 99709-56120

How to Use This Manual
This service manual contains the S6S Diesel Engine specifications, maintenance standards and adjustment
procedures as well as service procedures such as disassembly, inspection, repair and reassembly are arranged in
groups for quick reference.
There are separate manuals for the fuel injection pump and governor.
A short summary of each Group is given in the General Contents, and there is also a table of contents at the
beginning of each Group.
Regarding engine operation and periodical maintenance, refer to the Operation & Maintenance Manual. For
component parts and ordering of service parts, refer to the Parts Catalogue. Structure and function of the engine are
described in various training manuals.
1. Methods of Indication
(1) Parts shown in illustrations and described in text are numbered to correspond with the sequence of disassembly.
(2) Inspections to be conducted during disassembly are indicated in a box in disassembled views.
(3) Maintenance standards for inspection and repair are described in text where they are relevant, are also listed in
Group 2 in the General Contents.
(4) The sequence in which parts are to be assembled is summarized below each assembled view.
Such as: 52431
(5) The following marks are used in this manual to emphasize important safety cautions.
…Indicates a potentially hazardous situation which, if not avoided, could result in death or
serious injury.
…Indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury.
…Indicates important information or information which is useful for engine operation or
maintenance.
(6) Tightening torque under wet conditions is indicated by “[Wet].” When so indicated, apply engine oil to the
threaded portion of the fastener. Unless indicated as such, the tightening torque is to be assumed in the dry
condition.
←←←←
WARNING
CAUTION
NOTE

2. Terms Used in This Manual
Nominal value: Indicates the standard dimension of a part to be measured.
Standard: Indicates the dimension of a part, the clearance between parts, or the standard performance. Since the
value is indicated in a range needed for inspection, it is different from the design value.
Limit: A part must be repaired or replaced with a new part when it reaches the limit value.
3. Abbreviations, Standards, Etc.
• BTDC = Before Top Dead Center
• ATDC = After Top Dead Center
• BBDC = Before Bottom Dead Center
• ABDC = After Bottom Dead Center
• TIR = Total Indicated Reading
• API = American Petroleum Institute
• ASTM = American Society for Testing and Materials
• JIS = Japanese Industrial Standards
• LLC = Long Life Coolant
• MIL = Military Specifications and Standards (U.S.)
• MSDS = Material Safety Data Sheet
• SAE = Society of Automotive Engineers (U.S.)
4. Units of Measurement
Measurements are based on the International System of Units (SI), and their converted metric values are indicated in
parentheses ( ). For metric conversion, the following rates are used.
• Pressure: 1 MPa = 10.197 kgf/cm2
• Torque: 1 N·m = 0.10197 kgf·m
• Force: 1 N = 0.10197 kgf
• Horsepower: 1 kW = 1.341 HP = 1.3596 PS
• Meter of mercury: 1 kPa = 0.7 cmHg
• Meter of water: 1 kPa = 10.197 cmH2O (cmAq)
• Rotational speed: 1 min−1= 1 rpm

GROUP INDEX Items
1
2
3
4
5
6
7
8
9
10
11
12
13
GROUP INDEX
GENERAL Outline, Specifications, Tips on Disassembly and Reassembly
MAINTENANCE STANDARDS Maintenance Standards Table, Tightening Torques, Sealants and Lubricants,
Regarding Submission of Parts for EPA Exhaust Gas Regulation
SPECIAL TOOLS Special Tools
OVERHAUL INSTRUCTIONS Determination of Overhaul Timing, Testing the Compression Pressure
ADJUSTMENTS, BENCH TEST,
PERFORMANCE TESTS Adjustments, Bench Testing, Performance Tests
ENGINE AUXILIARIES
REMOVAL AND INSTALLATION Preparation, Engine Auxiliaries Removal, Engine Auxiliaries Installation
ENGINE MAIN PARTS Cylinder Head and Valve Mechanism, Flywheel, Damper, Timing Gears and
Camshaft, Piston, Connecting Rods, Crankshaft, Crankcase and Tappets
INLET AND EXHAUST SYSTEM Description, Exhaust Manifold
LUBRICATION SYSTEM Description, Oil Pump, Oil Filter, Oil Pressure Relief Valve
COOLING SYSTEM Description, Water Pump and Thermostat
FUEL SYSTEM Description, Fuel Filter (Paper-Element Cartridge Type), Injection Nozzles
ELECTRICAL SYSTEM Starter, Alternator, Glow Plug, Stop Solenoid
WORKSHOP TIPS Basic Recommended Assembly Procedures

1. Outline ................................................................................................. 1 – 1
1.1 External View .................................................................................. 1 – 1
1.2 Engine Serial Number Location ...................................................... 1 – 2
2. Specifications .................................................................................... 1 – 3
3. Tips on Disassembly and Reassembly ....................................... 1 – 5
3.1 Disassembly.................................................................................... 1 – 5
3.2 Reassembly ................................................................................... 1 – 5
1
GENERAL

1-1
GENERAL
1. Outline
1.1 External View
Remark: Direction of rotation of this engine is counterclockwise as seen from flywheel side.
Fuel feed pump
Water pump
Fuel filter
Stop solenoid
Relief valve
Fuel injection pump Oil level gauge
Fuel injection nozzle
Inlet manifold
Water drain plug
Flywheel
Oil filter
Oil pan
Oil drain plug
Front Rear
Left View
V-belt
Alternator
Exhaust manifold
Starter
Oil pressure switch
Rear Front
Right View

1-2
GENERAL
1.2 Engine Serial Number Location
The engine serial number is located on the side of the
crankcase.
Engine serial
number
Engine serial number location

2. Specifications
Model designation S6S
Type Water-cooled, 4-stroke cycle
No. of cylinders – arrangement 6 –in line
Combustion chamber type Swirl chamber
Valve mechanism Overhead
Cylinder bore × stroke mm (in.) 94 ×120 (3.70 ×4.72)
Piston displacement liter (cu in.) 4.996 (305)
Compression ratio 22 : 1
Firing order 1 – 5 – 3 – 6 – 2– 4
Direction of rotation Counterclockwise as viewed from flywheel side
Overall length 866 (34.1)
mm (in.)
Dimension Overall width 622 (24.5)
mm (in.)
Overall height 801 (31.5)
mm (in.)
Weight (dry) kg (lb) Approx. 340 (750)
Type of cylinder sleeve Integral with cylinder block
No. of piston ring Compression ring 2
Oil ring 1 (w/spring expander)
Inlet valve Open BTDC 30°
Close ABDC 50°
Valve timing
Exhaust valve Open BBDC 74°
Close ATDC 30°
Starting system Electric-starter
Starting aid Glow plug
Type Force feed by oil pump
API Service Classification CD or higher
Engine oil Refill capacity Whole system: Approx. 13.0 (3.4)
liter (U.S. gal.)
Type Trochoid
Speed ratio to crankshaft 0.74
Oil pump Capacity 38.7 (10.2) at 0.3 MPa (3 kgf/cm2) [42.7 psi]
liter (U.S gal.)/min discharge pressure of pump running at 2230 min-1
Oil pressure Type Piston valve
relief valve Opening pressure 0.35±0.05 (3.5±0.5) [50±7]
MPa (kgf/cm2) [psi]
Oil filter Type Cartridge of paper element
1-3
GENERAL
General
Engine main
parts
Lubrication
system

1-4
GENERAL
Model designation S6S
Refill capacity (engine water jacket) 9.0 (2.4)
liter (U.S. gal.)
Type Centrifugal
Water pump Speed ration to crankshaft 1.3
Capacity 160 (42.3) at 0.07 MPa (7.5 kgf/cm2) [107 psi]
liter (U.S gal.)/min/min-1 discharge pressure of pump running at 3600 min-1
Belt Type mm (in.) Low-edge B type V-belt × 1 1190 (46.9)
Type Wax pellet
Thermostat
Valve opening temperature
76.5±1.5 (170±2.7)
°C (°F)
Type Bosch A
Diameter of plunger 7 (0.276)
Injection pump mm (in.)
Cam lobe lift 8 (0.315)
mm (in.)
Governor Type Bosch RSV, centrifugal
Type of nozzle Bosch hole
No. of discharge orifice 1
Diameter of discharge 1.0 (0.039)
Injection nozzle orifice mm (in.)
Spray cone angle 0°
Valve opening pressure 11.77 (120) [1707]
MPa (kgf/cm2) [psi]
Fuel filter Type Cartridge of paper element
Voltage – polarity 24 V – (−) ground
Model M008T60372
Type Pinion shift
Starter Output V – kW 24 – 5
No. of pinion teeth/ 10/122
flywheel ring gear teeth
Type 3-phase, with rectifier
Output V – A 24 – 35
Working speed min-1 8000
Alternator Rated output generating 5000
speed min-1
Maximum permissible 10,000
speed min-1
Speed ratio to crankshaft 2.0
Type Electric
Glow plug Rated voltage – current 22 – 4.4 (1.5 sec rating)
V–A
Stop solenoid Rated voltage V 24
Electrical
system
Cooling system
Fuel system