Isuzu A-4JA1, 4ja1, A-4JB1 Workshop Manual

INDUSTRIAL

DIESEL ENGINE

A-4JA1, A-4JB1

MODELS

©

2003 ISUZU MOTORS LIMITED

WORKSHOP MANUAL

FOREWORD

This Workshop Manual is designed to help you perform necessary
maintenance, service, and repair procedures on applicable Isuzu
industrial engines.

Information contained in this Workshop Manual is the latest
available at the time of publication.

Isuzu reserves the right to make changes at any time without prior
notice.

This Workshop Manual is applicable to 1998 and later models.

NOTICE

Before using this Workshop Manual to assist you in
performing engine service and maintenance operations,
it is recommended that you carefully read and throughly
understand the information contained in Section - 1
under the headings “General Repair Instruction” and
“Notes on The Format of This Manual”

TABLE OF CONTENTS

SECTION 1. GENERAL INFORMATION.................................. 1

SECTION 2. MAINTENANCE ............................................. 17

SECTION 3. ENGINE ASSEMBLY (1) .................................... 29

(DISASSEMBLY)

SECTION 4. ENGINE ASSEMBLY (2) .................................... 47

(INSPECTION AND REPAIR)

SECTION 5. ENGINE ASSEMBLY (3) .................................... 81

(REASSEMBLY)

SECTION 6. LUBRICATING SYSTEM.................................... 109

SECTION 7. COOLING SYSTEM ......................................... 121

SECTION 8. FUEL SYSTEM............................................... 133

SECTION 9. ENGINE ELECTRICALS ..................................... 147

SECTION 10. TROUBLESHOOTING....................................... 175

SECTION 11. SPECIAL TOOL LIST ........................................ 201

SECTION 12. REPAIR STANDARDS....................................... 205

SECTION 13. CONVERSION TABLE....................................... 219

GENERAL INFORMATION

1

SECTION 1

GENERAL INFORMATION

TABLE OF CONTENTS

ITEM PAGE

General repair instructions ....................................................... 2

Notes on the format of this manual................................................. 2

Main data and specifications....................................................... 6

Tightening torque specifications ................................................... 7

GENERAL INFORMATION

GENERAL REPAIR INSTRUCTIONS

1. Before performing any service operation with the engine mounted, disconnect the grounding cable
from the battery.

This will reduce the chance of cable damage and burning due to short circuiting.

2. Always use the proper tool or tools for the job at hand.
Where specified, use the specially designed tool or tools.

3. Use genuine ISUZU parts.

4. Never reuse cotter pins, gaskets, O-rings, lock washers, and self locking nuts. Discard them as you
remove them. Replace them with new ones.

5. Always keep disassembled parts neatly in groups. This will ensure a smooth reassembly operation.
It is especially important to keep fastening parts separate. These parts vary in hardness and design,

depending on their installation position.

6. All parts should be carefully cleaned before inspection or reassembly.
Oil ports and other openings should be cleaned with compressed air to make sure that they are

completely free of obstructions.

7. Rotating and sliding part surfaces should be lubricated with oil or grease before reassembly.

8. If necessary, use a sealer on gaskets to prevent leakage.

9. Nut and bolt torque specifications should be carefully followed.

10. Always release the air pressure from any machine-mounted air tank(s) before dismounting the engine
or disconnecting pipes and hoses. To not do so is extremely dangerous.

11. Always check and recheck your work. No service operation is complete until you have done this.

NOTES ON THE FORMAT OF THIS MANUAL

This Workshop Manual is applicable to ISUZU industrial engine or engines which is or are stated in the
title.

When more than two engine models are dealt in the manual, such engines have common parts and
components as well as data and specifications, unless otherwise specified.

1. Find the applicable section by referring to the Table of Contents at the beginning of the Manual.

2. Common technical data such as general maintenance items, service specifications, and tightening
torques are included in the "General Information" section.

The section ENGINE ASSEMBLY is an exception. This parts are divided in three sections to facilitates
indexing.

3. Each section is divided into sub-sections dealing with disassembly, inspection and repair, and
reassembly.

2

GENERAL INFORMATION

3

4. When the same servicing operation is applicable to several different units, the manual will direct you
to the appropriate page.

5. For the sake of brevity, self-explanatory removal and installation procedures are omitted.
More complex procedures are covered in detail.

6. Each service operation section in this Workshop Manual begins with an exploded view of the
applicable area. A brief explanation of the notation used follows.

15

14

16

17

11

12

13

3

9

10

5

4

8

7

6

2

1

★

★Repair kit

★

★

★

★

★

Disassembly Steps - 2

1. Water by-pass hose

2. Thermostat housing

3. Water pump

▲ 4. Injection nozzle holder

5. Glow plug and glow plug connector

6. Cylinder head cover

▲ 7. Rocker arm shaft and rocker arm

8. Push rod

▲ 9. Cylinder head

10. Cylinder head gasket

▲ 11. Crankshaft damper pulley with

dust seal

12. Timing gear case cover

13. Timing gear cover

14. Timing gear oil pipe

15. Idler gear “B” and shaft

▲ 16. Idler gear “A”

17. Idler gear shaft

Inverted Engine

Parts marked with an asterisk (*) are
included in the repair kit.

Parts within a square frame are to be
removed and installed as a single unit,
and their disassembly steps or reas­sembly steps are shown in the
illustrations respectively.

The number tells you the service oper­ation sequence.

Removal of unnumbered parts is unne­cessary unless replacement is required.

The "* Repair Kit" indicates that a repair
kit is available.

The parts listed under "Disassembly
Steps" or "Reassembly Steps" are in the
service operation sequence.

The removal or installation of parts
marked with a triangle (▲) is an
important operation. Detailed infor­mation is given in the text.

GENERAL INFORMATION

4

8. The following symbols appear throughout this Workshop Manual. They tell you the type of service
operation or step to perform.

.... Removal .... Adjustment

.... Installation .... Cleaning

.... Disassembly ... Important operation requiring extra care

.... Reassembly .... Specified torque (tighten)

.... Alignment (marks) ....

Special tool use required or
recommended(Isuzu tool or tools)

.... Directional indication ....

Commercially available tool use
required or recommended

.... Inspection .... Lubrication (oil)

.... Measurement .... Lubrication (grease)

.... Sealant application

7. Below is a sample of the text of the Workshop Manual.

4. Camshaft Timing Gear

1) Install the thrust plate 1 .

2) Apply engine oil to the bolt threads 2 .

3) Install the camshaft timing gear with the timing
mark stamped side facing out.

Camshaft Timing Gear Bolt Torque kgf·m(lb.ft/N·m)

11.0 ± 1.0 (79.5 ± 7.2/107.8 ± 9.8)

1

2

13. Crankshaft Rear Oil Seal

1) Apply engine oil to the oil seal lip circumference
and the oil seal outer circumference.

2) Use the oil seal installer to install the oil seal to
the cylinder body.

Oil Seal Installer: 5-8840-0141-0

14. Flywheel Housing

1) Apply liquid gasket to the shaded area shown in
the illustration.

2) Tighten the flywheel housing bolts to the speci­fied torque a little at a time in the sequence
shown in the illustration.

Flywheel Housing Bolt Torque kgf·m(lb.ft/N·m)

M10x1.25 (0.40x0.05) Bolt 5.6±1.0 (40.5±7.2/ 54.9±9.8)
M12x1.25 (0.47x0.05) Bolt 10.5±1.0 (76.0±7.2/103.0±9.8)
M12x1.75 (0.47x0.07) Bolt 9.8±1.0 (71.0±7.2/ 96.0±9.8)

7

4

8

6

10

9

3

2

1

5

This is the item shown in the illus­tration. It is marked with a triangle
(▲) on the Major Components page.

Letters and numbers contained in a
circle refer to the illustration.

Special tools are identified by the
tool name and/or number.

The illustration shows how the spe­cial tool is to be used.

Symbols indicate the type of service
operation or step to be performed. A
detailed explanation of these
symbols follows.

Service data and specifications are
given in this table.

GENERAL INFORMATION

9. Measurement criteria are defined by the terms "standard" and "limit".
A measurement falling within the "standard" range indicates that the applicable part or parts are

serviceable.
"Limit" should be thought of as an absolute value.
A measurement which is outside the "limit" indicates that the applicable part or parts must be either

repaired or replaced.

10. Components and parts are listed in the singular form throughout the Manual.

11. Directions used in this Manual are as follows:
Front
The cooling fan side of the engine viewed from the flywheel.
Right
The right hand side viewed from the same position.
Left
The left hand side viewed from the same position.
Rear
The flywheel side of the engine.
Cylinder numbers are counted from the front of the engine.
The front most cylinder is No. 1 and rear most cylinder is the final cylinder number of the engine.
The engine's direction of rotation is counterclockwise viewed from the flywheel.

5

GENERAL INFORMATION

MAIN DATA AND SPECIFICATIONS

6

Engine Model

A-4JA1 A-4JB1 4JB1T

Item

Engine type Water cooled, four-cycle, in-line, overhead valve
Combustion chamber type Direct injection
Cylinder liner type Dry
No. of cylinders - Bore x Stroke mm(in.) 4 - 93.0 x 92.0 4 - 93.0 x 102.0 4 - 93.0 x 102.0

(3.66 x 3.62) (3.66 x 4.02) (3.66 x 4.02)
Total piston displacement lit(cid) 2.449 (152.4) 2.771 (169.0) 2.771 (169.0)
Compression ratio (To 1) 18.4 18.2 18.2

*Engine dimensions mm(in.) 805 x 625 x 729 739 x 625 x 746 578 x 771 x 577

Length x Width x Height (31.7 x 24.6 x 28.7) (29.1 x 24.6 x 29.4) (22.8 x 30.4 x 22.7)

*Engine weight (Dry) kg(lb.) 218 (480) 220 (486) 245 (540)

Fuel injection order 1 – 3– 4 – 2

*Fuel injection timing (B.T.D.C.) degrees 14

Specified fuel Diesel fuel
Injection pump In-line plunger, Bosch A type Bosch distributor

VE type

Governor Variable speed mechanical type

*Low idle speed rpm 850 – 1,000

Injection nozzle Multi-hole type
Injection starting pressure kgf/cm2(psi/MPa) 185 (2630/18.1)
Fuel filter type Cartridge papaer element
Water sedimentor (if so equipped) Sediment/water level indicating type
Compression pressure kgf/cm2(psi/MPa) 31 (441/3.04)
Valve clearance (at cold) Intake mm(in.) 0.40 (0.0157)

Exhaust mm(in.) 0.40 (0.0157)
Lubrication method Pressurized circulation
Oil pump Trochoid type
Main oil filter type Cartridge paper element, full flow
Partial oil filter Not equipped

*Lubricating oil volume lit.(qts) 5.5 (5.8) – 6.6 (7.0) 4.6 (4.9) – 6.4 (6.8) 4.6 (4.9) – 6.3 (6.7)

Oil cooler (if so equipped) Water cooled built in oil filter
Cooling method Pressurized forced circulation
Coolant volume lit.(qts) 5.0 (5.3)
Water pump Belt driven impeller type
Thermostat type Wax pellet type

*Alternator V-A 12 – 35
*Starter V-kW 12 – 2.2

Specifications marked with an asterisk (*) will vary according to engine application.

GENERAL INFORMATION

7

TIGHTENING TORQUE SPECIFICATIONS

The tightening torque values given in the table below are applicable to the bolts unless otherwise
specified.

STANDARD BOLT kgf·m (lb.ft/N·m)

An asterisk (*) indicates that the bolts are used for female threaded parts that are made of soft materials
such as casting. Those shown in parentheses in the strength class indicate the classification by the old
standard.

M 6 × 1.0

M 8 × 1.25

M10 × 1.25

M12 × 1.25

M14 × 1.5

M16 × 1.5

M18 × 1.5

M20 × 1.5

M22 × 1.5

M24 × 2.0

*M10 × 1.5

*M12 × 1.5

*M14 × 2.0

*M16 × 2.0

0.4 – 0.8

(2.9 – 5.8/3.9 – 7.8)

0.8 – 1.8

(5.8

–

13.0/7.8– 17.7)

2.1 – 3.5

(15.2– 25.3/20.6– 34.3)

5.0

–

7.5

(36.2

–

54.2/49.0– 73.6)

7.8

–

11.7

(56.4

–

84.6/78.5– 114.7)

10.6

–

16.0

(76.7

–

115.7/103.0– 156.9)

15.4

–

23.0

(111.1

–

166.4/151.0– 225.6)

21.0

–

31.6

(151.9

–

228.6/205.9– 307.9)

25.6

–

42.2

(185.2

–

305.2/251.1– 413.8)

36.6

–

55.0

(264.7

–

397.8/358.9– 539.4)

2.0

–

3.4

(14.5

–

24.6/19.6– 32.4)

4.6

–

7.0

(33.3

–

50.6/45.1– 68.7)

7.3

–

10.9

(52.8

–

78.8/71.6– 106.9)

10.2

–

15.2

(73.8

–

110.0/100.0– 149.1)

0.5

–

1.0

(3.6

–

7.2/4.9– 9.8)

1.2

–

2.3

(8.7

–

16.6/11.8– 22.6)

2.8

–

4.7

(20.3

–

34.0/27.5– 46.1)

6.2

–

9.3

(44.8

–

67.3/60.8– 91.2)

9.5

–

14.2

(68.7

–

102.7/93.2– 139.3)

13.8

–

20.8

(99.8

–

150.4/135.3– 204.0)

19.9

–

29.9

(143.9

–

216.3/195.2– 391.3)

27.5

–

41.3

(198.9

–

298.7/269.7– 405.0)

37.0

–

55.5

(267.6

–

401.4/362.9– 544.3)

43.9

–

72.5

(317.5

–

523.9/430.5– 711.0)

2.8

–

4.6

(20.3

–

33.3/27.5– 45.1)

5.8

–

8.6

(42.0

–

62.2/56.9– 84.3)

9.0

–

13.4

(65.1

–

96.9/88.3– 131.4)

13.2

–

19.8

(95.5

–

143.2/129.5 – 194.2)

1.7

–

3.1

(12.3

–

22.4/16.7– 30.4)

3.8

–

6.4

(27.5

–

46.3/37.3– 62.8)

7.7

–

11.6

(55.7

–

83.9/75.5– 113.8)

11.6

–

17.4

(83.9

–

125.6/113.8– 170.6)

16.3

–

24.5

(118.9

–

177.2/159.9– 240.3)

23.4

–

35.2

(169.3

–

254.6/229.5– 345.2)

32.3

–

48.5

(233.6

–

350.8/316.8– 475.6)

43.3

–

64.9

(313.2

–

469.4/424.6– 636.5)

56.5

–

84.7

(408.7

–

612.6/554.1– 830.6)

3.7

–

6.1

(26.8

–

44.1/36.3– 59.8)

7.3

–

10.9

(52.8

–

78.8/71.6– 106.9)

10.9

–

16.3

(78.8

–

118.9/106.9– 159.9)

15.6

–

23.4

(112.8

–

169.3/162.8– 229.5)

Refined

No mark

Non-Refined

4.8 (4T)

8.8(7T)

9.8 (9T)

Strength

Class

Bolt
Identification

Bolt
Diameter ×
pitch (mm)

GENERAL INFORMATION

8

TIGHTENING TORQUE SPECIFICATIONS

The tightening torque values given in the table below are applicable to the bolts unless otherwise
specified.

FLANGED HEAD BOLT kgf·m (lb.ft/N·m)

M 6 × 1

0.5– 0.9 0.6 – 1.2

(3.61– 6.50/4.6

–

8.5 (4.33 – 8.67/5.88 – 11.76)

M 8 × 1.25

1.1

–

2.0 1.4

–

2.9 1.9– 3.4

(7.95– 14.46/10.78– 19.61) (4.33– 8.67/5.88– 11.76) (13.74– 24.59/18.63– 33.34)

M10 × 1.25

2.3

–

3.9 3.6– 6.4 4.3– 7.2

(17.35– 28.20/23.53– 38.24) (26.03– 44.12/35.30– 59.82) (31.10– 52.07/42.16– 70.60)

*M10 × 1.5

2.3

–

3.8 3.5– 5.8 4.1– 6.8

(16.63

–

27.48/22.55– 37.26) (25.31– 41.95/34.32– 56.87) (29.65– 49.18/40.20– 66.68)

M12 × 1.25

5.6– 8.4 7.9– 11.9 8.7– 13.0

(40.50

–

60.75/54.91– 82.37) (57.14– 86.07/77.47– 116.69) (62.92– 94.02/85.31– 127.48)

*M12 × 1.75

3.5

–

9.5 7.3– 10.9 8.1– 12.2

(37.61– 56.41/50.99– 76.49) (52.80– 78.83/71.58– 106.89) (58.58– 88.24/79.43– 119.64)

M14 × 1.5

8.5

–

12.7 11.7– 17.6 12.6– 18.9

(61.48

–

91.85/83.35– 124.54) (84.62– 127.30/114.73– 172.59) (91.13– 136.70/123.56– 185.34)

*M14 × 2

7.6– 11.5 11.1– 16.6 11.8– 17.7

(57.14

–

85.34/77.47– 115.71) (80.28– 120.06/108.85– 162.79) (85.34– 128.02/115.71– 173.57)

M16 × 1.5

11.8– 17.7 17.1

–

26.5 18.0

–

27.1

(85.34

–

128.02/115.71– 173.57) (125.85– 189.50/170.63– 256.93) (130.19– 196.01/176.52– 265.76)

*M16 × 2

11.2– 16.7 16.6– 24.9 17.2– 25.7

(81.00

–

120.79/109.83

–

163.77) (120.06

–

180.10/162.79– 244.18) (124.40– 186.61/168.67– 253.01)

A bolt with an asterisk (*) is used for female screws of soft material such as cast iron.

Bolt head

marking

Nominal
size
(dia. x pitch)

GENERAL INFORMATION

9

SPECIAL PARTS FIXING NUTS AND BOLTS

Cylinder Head Cover, Cylinder Head, and Rocker Arm Shaft Bracket

kgf·m(lb.ft./N·m)

1.0 – 2.0

(7.2 – 14.4/9.8 – 19.6)

0.8 – 1.8

(5.8 – 13.0/7.8 – 17.6)

1st Step 2nd Step

3.0 – 5.0

(21.7 – 36.1/29.4 – 49.0)

8.2 – 9.2

(59.4 – 66.5/80.4 – 90.2)

8.0 – 9.0

(57.9 – 65.1/78.4 – 88.2)

10.0 – 11.0

(72.4 – 79.6/98.1 – 107.9)

5.0 – 6.0

(36.2 – 43.4/49.0 – 58.8)

New bolt

Reused
bolt

GENERAL INFORMATION

10

Crankshaft Bearing Cap, Connecting Rod Bearing Cap,
Crankshaft Damper Pulley, Flywheel, and Oil Pan

kgf·m(lb.ft./N·m)

8.0 – 9.0

(57.9 – 65.1/78.4 – 88.2)

16.0 – 18.0

(115.7 – 130.2/159.6 – 176.5)

20.1 – 24.5

(145.4 – 177.2/197.1 – 240.3)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

11.5 – 12.5

(83.2 – 90.4/112.8 – 122.6)

14 – 24

(1.4 – 2.4/4.4 – 7.2)

GENERAL INFORMATION

11

Timing Gear Case, Flywheel Housing, Camshaft, and Timing Gear

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

10.0 – 12.0

(72.4 – 86.8/98.1 – 117.7)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.0 – 1.5

(7.2 – 10.9/9.8 – 14.7)

6.6 – 8.7

(48 – 63/66 – 85)

M10 x 1.25 (0.39 x 0.05) 4.6 – 6.6 (33.3 – 47.7/45.1 – 64.7)

9.6 – 11.6 (69.4 – 83.9/94.1 – 113.8)

8.8 – 10.8 (63.7 – 78.1/86.3 – 105.9)

M12 x 1.25 (0.47 x 0.05)
M12 x 1.75 (0.47 x 0.07)

GENERAL INFORMATION

12

Cooling and Lubricating System

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

GENERAL INFORMATION

13

Intake and Exhaust Manifold

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

GENERAL INFORMATION

14

Engine Electrical

kgf·m(lb.ft./N·m)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

3.6 – 4.6

(26.0 – 33.3/35.3 – 45.1)

2.0 – 2.5

(14.4 – 18.1/19.6 – 24.5)

6.0 – 8.0

(43.4 – 57.9/58.8 – 78.4)

GENERAL INFORMATION

15

Fuel Injection System

kgf·m(lb.ft./N·m)

3.2 – 4.4

(23.1 – 31.8/31.4 – 43.2)

20 – 4.0

(14.4 – 28.9/19.6 – 39.2)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

1.4 – 2.4

(10.1 – 17.3/13.7 – 23.5)

16

MEMO

MAINTENANCE

17

SECTION 2

MAINTENANCE

TABLE OF CONTENTS

ITEM PAGE

Model identification ............................................................. 18

Injection pump identification ...................................................... 18

Lubricating system .............................................................. 18

Fuel system .................................................................... 19

Cooling system ................................................................. 22

Valve clearance adjustment ....................................................... 23

Injection timing ................................................................. 24

Compression pressure measurement ............................................... 26

Recommended lubricants ......................................................... 27

Engine repair kit ................................................................ 28

MAINTENANCE

MAINTENANCE

Servicing refers to general maintenance procedures to be performed by qualified service personnel.
Maintenance interval such as fuel or oil filter changes should be refered to “INSTRUCTION MANUAL”.

MODEL IDENTIFICATION

Engine Serial Number

The engine number is stamped on the rear left hand side
of the cylinder body.

INJECTION PUMP IDENTIFICATION

Injection volume should be adjusted after referring to
the adjustment data applicable to the injection pump
installed.

The injection pump identification number (A) is stamped
on the injection pump identifications plate.

Note:

Always check the identification number before beginn­ing a service operation.

Applicable service data will vary according to the ident­ification number. Use of the wrong service data will
result in reduced engine performance and engine
damage.

1 ZEXEL (Manufacturer of the injection pump) identifi-

cation number

2 ISUZU Parts Number

Pump No. . . . . . . . . . . . . . .

NP - PE . . . . . . . . . . . . . . . . . . . . . .

(LICENCE BOSCH)

A

A

…Identification number

In-line type

LUBRICATING SYSTEM

Main Oil Filter
Replacement Procedure

1. Loosen the drain plug to drain the engine oil.

2. Wait a few minutes and then retighten the drain
plug.

3. Loosen the used oil filter by turning it counterclock­wise with a filter wrench.

Filter Wrench

18

Distributor type

MAINTENANCE

4. Clean the oil cooler fitting face.
This will allow the new oil filter to seat properly.

5. Apply a light coat of engine oil to the O-ring.

6. Turn in the new oil filter until the filter O-ring is
fitted against the sealing face.

7. Use a filter wrench to turn in the filter an additional
1 and 1/4 of a turn.

Filter Wrench

8. Check the engine oil level and replenish to the spec­ified level if required.

9. Start the engine and check for oil leakage from the
main oil filter.

FUEL SYSTEM

Fuel Filter
Replacement Procedure

1. Loosen the used fuel filter by turning it counter­clockwise with the filter wrench.

Filter Wrench

2. Clean the upper cover fitting face.
This will allow the new fuel filter to seat properly.

3. Apply a light coat of engine oil to the O-ring.

4. Supply fuel to the new fuel filter to facilitate bleed­ing.

5. Turn in the new fuel filter until the filter O-ring is fit­ted against the sealing face.

Be very careful to avoid fuel spillage.

6. Use a filter wrench to turn in the fuel filter an addi­tional 1/3 to 2/3 of a turn.

19

MAINTENANCE

Water Separator (Water Sedimentor)
(Optional Equipment)

Check the water separator float 1 level.
If the float 1 has reached level 2 , loosen the drain plug
3 (at the bottom side of the water separator) to drain
the water.

Drain Plug Torque kgf·m(lb.ft./N·m)

0.9 – 1.5 (6.5 – 10.9/8.8 – 14.7)

1

2

3

Air Bleeding

1. For the engine equipped with in-line type injection
pump

1) Loosen the priming pump cap 1 on the injection
pump.

2) Loosen the fuel return eye bolt 2 on the fuel filter.

3) Operate the priming pump until there are no more
bubbles visible in the fuel being discharged from the
fuel return eye bolt on the fuel filter.

4) Retighten the fuel return eye bolt on the fuel filter.

5) Loosen the bleeder bolt 3 while operating the
injection pump priming pump to check that the air
has been bled completely.

6) Operate the priming pump several times to check for
fuel leakage around the injection pump and the fuel
filter.

2. For the engine equipped with distributor type injec­tion pump

1) Loosen the bleeder screw on the injection pump
overflow valve.

2) Operate the priming pump until fuel mixed with
foam flows from the bleeder screw.

3) Tighten the bleeder screw.

4) Operate the priming pump several times and check
for fuel leakage.

20

080ES004

Air bleeding screw

MAINTENANCE

Injection Nozzle
Injection Nozzle Inspection

Use a nozzle tester to check the injection nozzle opening
pressure and the spray condition.

If the opening pressure is above or below the specified
value, the injection nozzle must be replaced or recondi­tioned.

If the spray condition is bad, the injection nozzle must be
replaced or reconditioned.

Injection Nozzle Opening Pressure kgf/cm2(psi/MPa)

185 (2,630/18.1)

Spray Condition

(1) Correct
(2) Incorrect (Restrictions in orifice)
(3) Incorrect (Dripping)

Injection Nozzle Adjustment

1. Clamp the injection nozzle in a vise.

2. Use a wrench to remove the injection nozzle retain­ing nut.

3. Install the injection nozzle 1 , the push rod 2 , the
spring 3 , and adjusting shim 4.

Retaining Nut Torque kgf·m(lb.ft./N·m)

4.0 – 5.0 (28.9 – 36.2/39.2 – 49.0)

4. Attach the injection nozzle holder to the injection
nozzle tester.

5. Apply pressure to the nozzle tester to check that the
injection nozzle opens at the specified pressure.

If the injection nozzle does not open at the specified
pressure, install or remove the appropriate number
of adjusting shims to adjust it.

Adjusting Shim Availability mm(in.)

Range 0.50 – 1.50 (0.02 – 0.06)
Increment 0.025 (0.001)

Total No. of Shims 40

(Reference)
Removing or installing one shim will increase or

decrease the nozzle opening pressure approximately

3.77 kgf/cm2(53.6 psi/370kPa).

WARNING:

TEST FLUID FROM THE INJECTION NOZZLE TESTER
WILL SPRAY OUT UNDER GREAT PRESSURE. IT CAN
EASILY PUNCTURE A PERSON’S SKIN. KEEP YOUR
HANDS AWAY FROM THE INJECTION NOZZLE TESTER
AT ALL TIMES.

21

1

2 3

1

2

3

4

MAINTENANCE

COOLING SYSTEM

Cooling Fan Drive Belt

Fan belt tension is adjusted by moving the alternator.

A Crankshaft damper pulley
B Alternator pulley
C Cooling fan drive pulley
D Depress the drive belt mid-portion with a 10 kgf (22

lb/98 N) force.

Drive Belt Deflection mm(in.)

10.0 (0.39)

A

C

D

B

Thermostat
Operating Test

1. Completely submerge the thermostat in water.

2. Heat the water.
Stir the water constantly to avoid direct heat being

applied to the thermostat.

3. Check the thermostat initial opening temperature.

Thermostat Initial Opening Temperature °C(°F)

82 (180)

4. Check the thermostat full opening temperature.

Thermostat Full Opening Temperature °C(°F)

95 (203)

Valve Lift at Fully Open Position mm(in.)

8.0 (0.315)

1 Thermostat
2 Agitating Rod
3 Wooden Piece

1

2

3

22

MAINTENANCE

VALVE CLEARANCE ADJUSTMENT

1. Retighten the rocker arm shaft bracket bolts in
sequence as shown in the illustration.

Rocker Arm Shaft Bracket Bolt
Torque kgf·m(lb.ft/N·m)

5.0 – 6.0 (36.2 – 43.4/49.0 – 58.8)

3124

2. Bring the piston in either the No. 1 cylinder or the
No. 4 cylinder to TDC on the compression stroke by
turning the crankshaft until the crankshaft damper
pulley TDC line is aligned with the timing pointer.

TDC

3. Check for play in the No. 1 intake and exhaust valve
push rods.

If the No. 1 cylinder intake and exhaust valve push
rods have play, the No. 1 piston is at TDC on the
compression stroke.

If the No. 1 cylinder intake and exhaust valve push
rods are depressed, the No. 4 piston is at TDC on the
compression stroke.

Adjust the No. 1 or the No. 4 cylinder valve clearances
while their respective cylinders are at TDC on the com­pression stroke.

Valve Clearance mm(in.)

0.40 (0.016)

Loosen each valve clearance adjusting screw as shown
in the illustration. (At TDC on the compression stroke of
the No. 1 cylinder)

Insert a feeler gauge of the appropriate thickness
between the rocker arm and the valve stem end.

4. Turn the valve clearance adjusting screw until a
slight drag can be felt on the feeler gauge.

5. Tighten the lock nut securely.

23

MAINTENANCE

Rotate the crankshaft 360°.
Realign the crankshaft damper pulley TDC line with the

timing pointer.
Adjust the clearances for the remaining valves as shown

in the illustration. (At TDC on the compression stroke of
the No. 4 stroke)

INJECTION TIMING

Injection Timing Confirmation Procedure

1. In-line type injection pump

1) Rotate the crankshaft clockwise to align the cam ­shaft gear timing mark “O” with the timing gear
case cover pointer.

The No. 1 cylinder will now be at the point where
nearly injection timing.

2) Remove the No. 1 fuel injection pipe.

3) Remove the delivery valve holder 1 , the delivery
valve spring 2 , and the delivery valve 3 .

4) Tighten the delivery valve holder to the specified
torque.

Delivery Valve Holder Torque kgf·m(lb.ft/N·m)

4.0 – 4.5 (28.9 – 32.5/39.2 – 44.1)

1

2

3

5) Operate the injection pump priming pump while
slowly rotating the crankshaft until fuel stops flow­ing from the delivery valve holder.

6) Conform that the crankshaft damper pulley notched
line is aligned with the timing gear case cover
pointer.

Injection Timing (Static BTDC)

14°

TDC 17

24

7) Remove the delivery valve holder.

8) Install the delivery valve 1 , the delivery valve
spring 2 , and the delivery valve holder 3 .

9) Tighten the delivery valve holder to the specified
torque.

10) Install the fuel injection pipes and tighten them to
the specified torque.

Fuel Injection Pipe Torque kgf·m(lb.ft/N·m)

2.0 – 4.0 (14.4 – 28.9/19.6 – 39.2)

11) Operation to air breeding.

1

2

3

MAINTENANCE

25

2. Distributor type injection pump

1) Rotate the crankshaft clockwise to align the cam ­shaft gear timing mark “O” with the timing gear
case cover pointer.

The No. 1 cylinder will now be at the point where
nearly injection timing.

2) Remove injector pump distributor head plug.

3) Fit a dial gauge and set lift to 1 mm (0.039 in).

4) Set crankshaft damper pulley Top Dead Center mark
about 45° before Top Dead Center from the pointer.

5) Set dial gauge in the “0” position.
Measuring device: 5-8840-0145-0

6) Turn the crankshaft a little rightwise and leftwise
and see if the pointer is stable in the “0” position.

7) Turn the crankshaft in the normal direction and read
the measuring device’s indication at TDC.

Starting Timing mm(in.)

0.5 (0.02)

8) If the injection timing is outside the specified range,
continue with the following steps.

9) Loosen the injection pump fixing nuts and bracket
bolts.

10) Adjust the injection pump setting angle.

• If injection timing will be advanced, move the

injection pump away from the engine.

• If injection timing will be retarded, move the

injection pump toward the engine.

Tighten the pump fixing nut, adjust bolt and pump
distribution head plug to the specified torque.

Pump Fixing Bolt kgf·m(lb.ft/N·m)

1.9 (13.7/18.6)

Injection Pump
Distributor Head Plug kgf·m(lb.ft/N·m)

1.7 (12.3/16.7)

080ES002

080ES003

MAINTENANCE

26

4. Set a compression gauge to the No. 1 cylinder glow
plug hole.

5. Turn the engine over with the starter motor and take
the compression gauge reading.

Compression Pressure kgf/cm2(psi/MPa) at 200 rpm

Standard Limit

31 (441/3.04) 22 (313/2.157)

COMPRESSION PRESSURE MEASUREMENT

1. Start the engine and allow it to run for several
minutes to warm it up.

2. Stop the engine and cut the fuel supply.

3. Remove all of the glow plugs from the engine.

Compression Gauge :5-8840-2675-0
Adapter :5-8840-9029-0

MAINTENANCE

27

RECOMMENDED LUBRICANTS

ENGINE TYPE TYPES OF LUBRICANTS

Diesel engine oil

Without turbocharger

CC or CD grade

Diesel engine oil

With turbocharger

CD grade

ENGINE OIL VISCOSITY CHART

ENGINE OIL VISCOSITY GRADE – AMBIENT TEMPERATURE

[Single grade]

–0°C

(32°F)

15°C

(59°F)

25°C

(77°F)

30°C

(86°F)

–15°C

(5°F)

–30°C

(–22°F)

[Multi grade]

SAE 40

SAE 20, 20W

SAE 10W–30

SAE 15W–40, 20W–40

SAE 30

Ambient
Temperature

SAE 10W