JAC HFC4DA1-2C User manual

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
1
Contents
Chapter I Technical Characteristics of Engine ..........................................................................................................11
Section I Technical Requirements for Fuel, Oils, andAuxiliary Materials.....................................................11
Section II Main Technical Specification of Engine ............................................................................................14
Section III Performance Curve of Engine..........................................................................................................15
Section IV Main Checking andAdjustment Parameters..................................................................................16
Section V Tightening Torque for Critical Bolts of Engine.................................................................................17
Section VI Main Fitting Clearances andAllowable Wear Limits of Engine ...................................................21
Section VII Specification of Main Attachments and Accessories......................................................................24
Chapter II Maintenance for Main Structures of Engine...........................................................................................25
Section I Disassembly of Engine Assembly.........................................................................................................25
Section II Assembly of Engine .............................................................................................................................43
Section III Crankshaft and Flywheel System.....................................................................................................68
Section IV Piston and Connecting Rod Group...................................................................................................69
Section V Valve Distribution Mechanism ...........................................................................................................70
Section VI Lubrication System............................................................................................................................71
Section VII Cooling System .................................................................................................................................72
Section VIII Turbocharger and Inter-Cooler System........................................................................................73
Section IX EGR System........................................................................................................................................75
Section X Exhaust System....................................................................................................................................76
Chapter III Working Principle of Engine Control and Actuator Units...................................................................77
Section I Overview of Diesel Common Rail System ..........................................................................................77
Section II Working Principle of Low Pressure Fuel Line System ....................................................................79
Section III Working Theory of High Pressure Fuel Line..................................................................................82
Section IV Electronic Control Unit of High Pressure Common Rail System..................................................84
Chapter IV Engine Diagnosis ....................................................................................................................................109
Section I. Precautions.........................................................................................................................................109
Section II. Maintenance Procedures ................................................................................................................. 111
Section III. Fault Diagnosis................................................................................................................................113
Section IV. DTC List...........................................................................................................................................115
Section V. Fault Diagnosis for Electronic-Controlled Common Rail Diesel Engines....................................133

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Chapter I Technical Characteristics of Engine
Section I Technical Requirements for Fuel, Oils, and Auxiliary Materials
I. Diesel
HFC4DA1-2C diesel engine adopts electronically controlled, high pressure common rail, fuel injection system and
conforms to Euro-IV emission regulation and thus extends higher requirements over the fuel. To guarantee the
reliability of the fuel supply system, make sure to use the qualified clean diesel produced by national well-established
fuel company, in order to prevent the blockage or early wear of fuel injector due to poor fuel.
Add the fuel only at the well-established gas station. The use of poor diesel or other diesel intended for
other than vehicle engine application is strictly prohibited.
Make sure to use the fuel conforming to national standard GB 19147. The grade number of the diesel chosen is related
to the temperature of working environment. When the environment temperature is reduced, the paraffins within the
diesel will precipitate to block the fuel pipeline, leading to difficult fuel supply and start failure of the engine.
Therefore, choose different grade number of diesel depending on the environment temperature in different seasons
and regions, in accordance with the table shown below.
Environment temperature Above 5℃Above -5℃Above -10℃Above -25℃
Recommended grade
number of diesel 0# light diesel -10# light diesel -20# light diesel -35# light diesel
Notice!
The cam of the high pressure fuel pump is being lubricated by the fuel. Never cause engine flameout due to depletion
of fuel in the fuel tank, or it will lead to serious wear of the high pressure fuel pump. After adding new fuel, make sure
to firstly use manual fuel pump to bleed the air from the fuel pipe and high pressure fuel pump and thoroughly fill the
fuel pipe and high pressure fuel pump with fuel before starting the engine, in order to prevent the wear of high
pressure fuel pump due to fuel shortage.
Procedure for air bleeding and refueling:
1. Loosen the air bleeding screw;
2. Push down the manual fuel pump with hand and then release. Repeat above operation, till there is no air bleeding
out from the air bleeding screw;
3. Tighten the air bleeding screw and pump the fuel with manual fuel pump, till the fuel injection pump is thoroughly
filled with fuel.
The diesel filter embodies the fuel-water separation function:
The water content in the diesel will bring about great harm to the fuel system. Upon the detection that the diesel filter
water level warning lamp on the instrument panel lights up, it indicates the presence of waste water in the diesel filter.
The waste water shall be drained timely, or it will lead to the rusting and wear of high pressure fuel pump, high
pressure fuel rail, and fuel injector and bring about unnecessary losses.
Procedure for water drainage:
1. Unplug the water level sensor connector;
2. Loosen the water level sensor to drain the waste water, till the diesel flows out.

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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3. Tighten the water level sensor and plug the water level sensor connector.
II. Engine Oil
HFC4DA1-2C diesel engine shall use the diesel engine oil with the quality grade at API CH-4 or above, of which the
viscosity is related to the environment temperature. When the environment temperature is reduced, the viscosity of the
engine oil is increased to increase the start resistance so that the diesel engine can’t reach the start speed and cause
difficult start. Therefore, in different seasons and regions, choose the correct engine oil with different viscosity grade
under different environment temperature, in accordance with the table below.
Environment
temperature -15℃~40℃-20℃~30℃-30℃~25℃Extreme cold region
Engine oil
trademark 10W-40/50 or 15W-40 10W-30/40/50 5W-40/50 0W-40/50
Check engine oil level:
zStop the engine and wait for several minutes;
zPull out the engine oil dipstick;
zWipe the oil dipstick with clean cloth and re-insert the oil dipstick to the end;
zPull out the oil dipstick again and observe the engine oil level. Check whether the oil level is between the upper
and lower limits of the oil dipstick. If insufficient, add the engine oil.
Notice!
zMake sure to periodically check the engine oil level.
zThe apparatus used for refueling shall be clean.
zIn event of sudden rise or drop of engine oil level, check for cause immediately.
Uppe
r limi
t
Lower limit
N
otice: Make sure to horizontally park the vehicle while
measuring the engine oil level. Stop the engine and wai
t
for several minutes, till the engine oil can return to the oil
sump.

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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zNever mix different trademarks of engine oils.
zPeriodically replace the engine oil as per the maintenance regulations.
III. Coolant
Make sure to use clean automotive antifreeze coolant featuring antifreeze in winter, anti-boiling in summer, and
anti-corrosion, anti-rusting, and anti-scaling.
Take cautions during the operation:
a. Always use coolant throughout the year and pay attention to the use continuity of the coolant.
b. Depending on the temperature of the region in which the vehicle is used, choose the coolant with different freezing
point. The freezing point of the coolant shall be at least 10ºC below the lowest temperature of the region, in order to
maintain the antifreeze function.
c. Purchase the qualified coolant product, in order to prevent damaging the engine and causing unnecessary economic
losses due to use of disqualified product.
d. Never mix different trademarks of coolants nor use such mixed coolant, in order to prevent the chemical reaction
from impairing the respective comprehensive anti-corrosion performance.
e. Never add the hard water such as well water or running water. Upon the detection of suspended material, sediment,
or smelliness phenomenon in the coolant, it indicates that the coolant is deteriorated and becomes ineffective due to
chemical reaction. In such case, timely clean the cooling system and thoroughly replace the coolant.
f. The glycol coolant is one toxic substance and is harmful to the liver. Never swallow the coolant. In event of skin
exposure to the coolant, thoroughly clean with water immediately. In addition, the nitrite anti-corrosion additive in the
coolant is one carcinogenic substance. Do not dispose the used coolant randomly, in order to prevent contaminating
the environment.
Notice!
zUpon the detection of sudden drop in coolant level, check for cause immediately.
zThe cooling system is under pressurized state! Never open the cap of the coolant compensation tank or radiator
while the engine is still hot, or it will lead to scalding danger!

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section II Main Technical Specification of Engine
Model HFC4DA1-2C
Type Inline 4-cylinder, longitudinal layout, water-cooled, 4-stroke, turbocharged
inter-cooler, high pressure common rail, and direct injection engine
Nominal power/speed 85/3600（kw/rpm）
Top torque/speed 250/1800～2800(Nm/rpm)
Minimum fuel consumption
of external characteristic ≤218g/kw·h Top idling speed 4000rpm
Exhaust temperature (before
turbine) ≤700℃Idling speed 800±50 rpm
Number of cylinders × bore
× stroke: 4×93 mm×102 mm Total piston displacement 2.771 L
Compression ratio 17 ：1 Fuel grade -10#
Working sequence 1-3-4-2 Fuel supply advance
angle Electronically controlled
Flameout mode Fuel cut-off Engine mass 270kg
Emission limit (test value) China-IV emission standard
compliant Noise limit ≤95dB(A)
Engine oil trademark Above grade CH-4 Engine oil capacity 7.2L
Engine oil/fuel consumption ratio (24h at full speed) ≤0.10%
Temperature of engine oil in oil sump (under nominal working
condition) ≤130℃
Engine oil pressure Idling: ≥98 kPa
Coolant capacity 30L Applicable altitude ≤3500m
Thermostat type Wax type Maximum outlet temperature of
coolant ≤110℃
Thermostat opening
temperature 82℃Thermostat full open temperature 95℃
Applicable temperature
of diesel engine With heated cold starter and with heater plug in engine
Overall dimensions (L×W×H) 728.9mm×715.6mm×753.3mm Length of cylinder
block 479mm

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section III Performance Curve of Engine
0
50
100
150
200
250
300
1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600
转速（rpm）
扭矩（Nm）
0
10
20
30
40
50
60
70
80
90
功率（kw）
扭矩
功率
200
210
220
230
240
250
260
270
280
1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600
转速（rpm）
油耗率（g/kw.h）
0
5
10
15
20
25
油耗量（kg/h）
油耗率
油耗量
Torque
Power
Torque
Powe
r
Speed
Fuel consumption
Fuel consumption
Fuel consumption (g/kw.h) Fuel consumption (kg/h)
Speed

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section IV Main Checking and Adjustment Parameters
1、At rated power:
(1) Exhaust temperature (master pipe) (ºC)
(2) Thermostat opening temperature (ºC)
(3) Thermostat full open temperature (ºC)
(4) Temperature of engine oil in main oil way (ºC)
(5) Engine oil pressure (kPa)
≤700
82
95
≤130
400～600
2. Engine oil pressure at minimum stable speed (kPa) ≥98
3. Timing phase (in rotation angle of crankshaft)
(1) Open of intake valve (before top dead center)
(2) Close of intake valve (after bottom dead center)
(3) Open of exhaust valve (before bottom dead center)
(4) Close of exhaust valve (after top dead center)
24.5°
55.5°
54°
26°
4. Valve clearance (mm) 0.3～0.4

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section V Tightening Torque for Critical Bolts of Engine
Comparison Table of Tightening Torque for Critical Bolts☆
No. Description N．m
1 Fixing bolt of rockshaft 55
2 Heater plug 25
3 Nut and washer for fuel injector body 40
4 Fuel injector 34
5 Fixing bolt of thermostat housing assembly 25
6 Installation torque of rocker arm assembly 55
7 Camshaft thrust plate bolt 25
8 Camshaft timing gear bolt 110
9 Fixing bolt of rockshaft 50
10 Fixing bolt of engine oil pump filter screen assembly 20
11 Engine oil pump fixing bolt 20
12 Oil sump bolt 23.5
13 Flywheel baffle bolt 85
14 Flywheel bolt 25 for first step
70 for second step
120 for third step
15 Crankshaft bearing cap bolt 20 for first step
110 for second step
170 for third step
16 Tightening bolt of engine oil pump 25
17 Socket nut of engine oil pump 30
18 Torque for cylinder head bolt: 65 for first step
85 for second step
105 for third step
19 Rockshaft support bolt 55
20 Main bearing cap bolt 170
21 Torque for drive shaft nut 66
22 Transmission bracket nut 69
23 Clutch cover – flywheel housing bolt M10：46
M12：91
24 Engine rear bracket nut and bolt M10：40
M12：69
25 Front exhaust pipe bolt 37
26 Clutch working cylinder bolt 19

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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No. Description N．m
27 Belt pulley bolt 210
28 Fan pulley 12.5
29 Crankshaft bearing cap bolt 170
30 Connecting rod bearing cap bolt 25 for first step
85 for second step
31 Camshaft timing gear 110
32 Fuel injection pump nut 30
33 Idler gear bolt 20
34 Engine oil pipe perforated bolt 20
35 Crankshaft belt pulley bolt 210
36 Fan silicone oil clutch 12.5
37 Connecting rod bearing cap 20 for first step
85 for second step
38 Piston cooling oil pipe bolt M8×1.25 25
M6×1.00 7.5
39 Oil pressure regulation valve M6×1.5 30
40 Socket nut of engine oil pump 30
41 Engine oil pump assembly bolt 25
42 Oil sump bolt 23.5
43 Cylinder head bolt 65 for first step
85 for second step
105±5 for third step
44 Rockshaft support bolt 55
45 Tightening bolt of water outlet pipe 19
46 Protrusion size of water pump impeller 24.6mm
47 Fan center distance 79.2～79.8 m
48 Open temperature of thermostat valve 82 ℃
49 Full open temperature of thermostat valve 95℃
50 Open pressure of vacuum valve at center of radiator
cap valve seat
88．2～117．6 kPa
51 Water pump fixing bolt 25 N.m
52 Alternator fixing bolt 40 N.m
53 Alternator adjustment plate fixing bolt 25 N.m
54 Lock nut, A/C compressor idler gear 27 N.m
55 Nut of engine oil cooler water pipe 25
56 Oil drainage plug 80
57 Fixing bolt of oil pump assembly 20

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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No. Description N．m
58 Tightening socket nut 30
59 Bolt and nut of starter motor 81
60 Fixing nut of starter cable 9
61 Exhaust branch pipe bolt 30
62 Bolt of heat shield 25
63 Support bolt 40
64 Front exhaust pipe nut 40
65 Crankshaft belt pulley bolt 210
66 Exhaust pipe nut 67
67 Torque of engine bracket bolt M10：40
M12：69
68 Cylinder head cover nut 13
69 Connecting nut between turbocharger and exhaust
manifold
25
70 Connecting bolt between exhaust manifold and
cylinder head
30
71 Bolt of exhaust pipe heat shield 25
72 Connecting bolt of turbocharger air bleeding pipe 25
73 Perforated bolt of lubricating oil pipe M12：41
M14：55
Comparison Table for Standard Bolt Specification and Tightening Torque☆
Bolt Identification
Torque (N.m)
Specification
Less than grade 8.8
(low carbon steel)
Grade 8.8 (High
carbon steel)
Grade 10.9 (Alloy
steel)
M6×1.0 4~8 5~10 .......
M8×1.25 8~18 12~23 17~31
M10×1.25 21~35 28~47 38~64
M10×1.5 20~34 28~46 37~61
M12×1.25 50~75 62~93 77~116
M12×1.75 46~70 58~86 73~109
M14×1.5 78~117 95~142 116~174
M12×2.0 73~109 90~134 109~163
M16×1.5 106~160 138~208 163~245
M16×2.0 102~152 132~198 156~234
M18×1.5 154~230 199~299 234~352
M20×1.5 210~316 275~413 323~485

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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M22×1.5 256~422 370~555 433~649
M24×2.0 360~550 439~725 565~847

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section VI Main Fitting Clearances and Allowable Wear Limits of Engine
No. Name Standard Size (mm)
Fitting
nature
Assembly
Clearance for
New Engine
(mm)
Wear Limit
(mm)
1
Contact width between
valve and seat ring
Intake valve 1.7 2.2
Exhaust valve 2 2.5
2
Valve sinkage
Intake valve 0.73 1.28
Exhaust valve 0.71 1.2
3 Backlash 0.05-0.13 0.3
4 Axial run-out clearance of
idler gear A 0.07 0.2
5
Outside diameter of tappet 010.0
028.0
13−
−
Φ
Clearance 0.01～0.046 0.10
Tappet bore 018.0
0
13
+
Φ
6 Radial run-out of push rod 0.3
7 Deflection of rockshaft 0.3
8
Outside diameter of
rockshaft
0
02.0
19− Φ
Clearance 0.01～0.05 0.20
Rocker arm bore 03.0
01.0
19
+
+
Φ
9
Rod diameter of intake
valve
039.0
054.0
8
−
−
Φ
Clearance 0.039～0.071 0.20
Valve guide bore 017.0
0
8
+
Φ
10
Rod diameter of exhaust
valve
064.0
079.0
8
−
−
Φ
Clearance 0.064～0.096 0.25
Valve guide bore 017.0
0
8
+
Φ
11
Free height of valve spring 48
Perpendicularity of valve
spring Φ1.4
12
Outside diameter of idler
gear A shaft
025.0
055.0
55
−
−
ΦClearance 0.025～0.080 0.2
Inside diameter of idler gear
A bearing
03.0
0
55
+
Φ
13 Cylinder sleeve bore 065.0
020.0
93
+
+
Φ

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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No. Name Standard Size (mm)
Fitting
nature
Assembly
Clearance for
New Engine
(mm)
Wear Limit
(mm)
Name Standard Size (mm)
Fitting
nature
Assembly
Clearance for
New Engine
(mm)
Wear Limit
(mm)
13 Protrusion height of
cylinder sleeve 0～０.08
14
Axial run-out clearance of
camshaft
Clearance 0.05～0.13
0.20
Cam height of camshaft 42.02±0.05 0.38
15
Inside diameter of camshaft
bush
025.0
0
50
+
Φ
Clearance 0.025～0.080 0.12
Diameter of camshaft
journal
025.0
055.0
50
−
−
Φ
16 Deflection of cam bush 0.02 0.1
17
Outside diameter of piston
pin
0
005.0
34− Φ
Clearance 0.002～0.015 0.03
Piston pin bore 010.0
002.0
34
+
+
Φ
18
Thickness of connecting
rod large end
0
07.0
33− Φ
Clearance 0.175～0.320 0.35
Opening of crankshaft
connecting rod journal
250.0
175.0
33
+
+
Φ
19 Clearance of intake and
exhaust valves (cold state) Clearance 0.3～0.4
20
Main journal 068.0
086.0
70
−
−
Φ
Clearance 0.031～0.066 0.11
Main bush bore (after
assembly)
003.0
033.0
70
−
−
Φ
21
Outside diameter of piston
pin
0
036.0
34− Φ
Clearance 0.008～0.026 0.05
Inside diameter of
connecting rod bush
020.0
038.0
34
+
+
Φ
22
Crankshaft connecting rod
journal
070.0
085.0
53
−
−
Φ
Clearance 0.029～0.069 0.1
Connecting rod bush bore
(after assembly)
016.0
041.0
53
−
−
Φ
23
Grouping of piston outside
diameter
Grouping
clearance 0.053～0.075
Group A 92.957～92.968
Group B 92.968～92.979
Group C 92.979～92.990
Group D 92.990～93.001

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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No. Name Standard Size (mm)
Fitting
nature
Assembly
Clearance for
New Engine
(mm)
Wear Limit
(mm)
Grouping of cylinder sleeve
inside diameter (after
pressed-in)
Group A 93.021～93.032
Group B 93.032～93.043
Group C 93.043～93.054
Group D 93.054～93.065
24
Opening of piston ring
1st compression ring 0.2～0.4 1.5
2nd compression ring 0.65～0.85 1.5
Oil control ring 0.25～0.50 1.5
25
End clearance of piston ring
1st compression ring 0.078～0.139 0.15
2nd compression ring 0.045～0.09 0.15
Oil control ring 0.03～0.07 0.15

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Section VII Specification of Main Attachments and Accessories
Lubrication
system
Engine oil pump type Externally engaged gear pump
Flow rate of engine oil pump ≥23L/m (at 1,000r/m and 0.4MPa)
≥23L/m (at 1,800r/m and 0.44MPa)
Open pressure of engine oil pump
relief valve
0.7±0.08MPa
Engine oil filter type Filter element type
Cooling
system
Water pump type Centrifugal type
Flow rate and head of water pump
(water temperature at 80±5ºC)
Head ≥6.5m (at 3,000r/m) at 100L/min flow rate;
Head ≥12m (at 4,000r/m) at 120L/min flow rate;
Thermostat type Pellet thermostat
Temperature of thermostat Initial open: 82ºC; full open: 95ºC
Fan type Independent electric fan
Electric
system
Preheating plug type Ceramic type
Voltage of preheating plug 12V
Starter specification 12V，2.8kW
Alternator specification 14V，90A
Battery voltage 12V
Intake system Turbocharger
Radial flow variable section turbocharger
The top speed of turbocharger is ≤220,000r/m, with
turbocharger ratio at ≤2.2.
EGR
Type of EGR valve Position feedback type
Voltage of EGR valve position
sensor
5V
Electronically
controlled
common rail
fuel system
Fuel filter type Spin-on type, with fuel-water separator, manual fuel
delivery pump, and diesel heater
High pressure fuel pump BOSCH CP1H, radial three-plunger pump, with fuel
delivery fuel pump and solenoid valve control
Fuel injector BOSCH CRI2.2, solenoid valve control
High pressure common rail Maximum rail pressure: 160MPa
Electronic control unit (ECU) BOSCH EDC17, with working voltage at 12V
Crankshaft speed sensor Working clearance: 0.5～1.2mm
Camshaft position sensor Working clearance: 0.5～1.5
Air flowmeter HFM6, with working voltage at 12V and flow measurement
range at 40~840kg/h.
Water temperature sensor NTC type
Rail pressure sensor Voltage output: 0.5~4.5V
Accelerator pedal position sensor Voltage: 5V

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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Chapter II Maintenance for Main Structures of Engine
Section I Disassembly of Engine Assembly
I. Special Notices:
a) Before overhauling the engine, make sure to firstly disconnect the negative cable of the battery, or it will damage
the harness and other electric units;
b) Unless otherwise specified, rotate the ignition switch to LOCK position;
c) Whenever the air cleaner is disassembled, make sure to plug the intake port, in order to prevent the ingress of
foreign material, which may enter into cylinder and cause serious damage.
II. Disassembly Procedure
zTurn the ignition switch to LOCK position and disconnect the negative cable of the battery.
zOpen the oil drainage bolt of the oil sump and fully drain and collect the oil.
zFully drain the coolant.
zDisassemble the water inlet and outlet hoses of the engine.
zDisassemble the electronic control harness for engine ECU, engine, and complete vehicle.
zDisassemble the power supply wires for alternator, starter, and oil pressure and water temperature sensors.
zRemove the connecting hose between intake connecting pipe and air cleaner.
zLoosen the connecting pipe of inter-cooler.
zShut off the fuel pipeline and unplug the fuel pipe and return pipe.
zDisconnect the power supply of the radiator fan and when necessary loosen the radiator bracket and take out the
whole radiator.
zLoosen the clutch connecting pipe.
zDisassemble relevant connecting pipes of air conditioner and power steering pump.
zDisconnect the exhaust manifold and exhaust muffler pipe.
zLoosen the connecting mechanism between transmission and the complete vehicle.
zLoosen the fixing bolts between engine and transmission suspension bracket.
zSteadily lower the engine with elevator.
zLoosen the connecting bolts between engine and transmission and separate the transmission from the engine.

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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III. Illustration for Disassembly of Engine
1. Disassemble the flywheel.
a. Block the flywheel with flywheel clamp, loosen the
fixing bolts between damping pulley and flywheel, and
disassemble the flywheel assembly.
2. Disassemble the belt, air conditioner
compressor, and alternator and water
pump pulleys.
a. Use an open-end wrench to remove the fixing nuts of
engine fan and remove the cooling fan of the engine.
b. Loosen the alternator adjustment bolts and fixing bolts,
remove the fan clutch pulley and alternator belt, and
check the side face and toothed face of the belt for
normal state.
c. Remove the oil and vacuum pump oil return pipe
connectors.
d. Loosen the alternator fixing bolts and adjustment bolts
and disassemble the alternator belt. Check the
alternator belt for presence of aging, cracking, and
abnormal wear. If yes, replace the belt. Arrange the
parts disassembled orderly on the part shelf, remove
the alternator, use hand to rotate the alternator pulley,
and check the inside for presence of noise, stagnation,
and unbalance. Check the alternator for presence of
ablation and check the shaft for presence of abnormal
wear noise.
e. Disassemble the water pump pulley.

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3. Disassemble the exhaust system.
a. Disassemble the fixing bolts of turbocharger lubricating
oil pipe and disassemble the fixing clamp of return
hose.
b. Remove the exhaust pipe shield.
c. Remove the EGR cooler.
d. Remove the exhaust pipe and turbocharger assembly.
e. Remove the fixing bolts and nuts of exhaust pipe,
remove the exhaust manifold and turbocharger
subassembly, and remove the exhaust manifold gasket.
f. Check:
A) Whether the rotor of turbocharger rotates flexibly.
B) Whether the air compressor wheel is damaged,
observed from the inlet of air compressor.
C) Whether the air compressor interferences with the
housing, observed from the inlet of air compressor.
4. Disassemble the relevant accessories
of fuel system.

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a. Loosen the conical nut at fuel injector end and the
conical nut on fuel injection pump side (one is to
reversely tighten the fuel inlet of fuel injector and one is
to loosen the nut of high pressure fuel pipe); Loosen the
conical nut on fuel injection pump side (Two wrenches
are used mainly for disassembly, of which one is to
reversely tighten the fuel outlet of fuel injection pump
and one is to loosen the nut of high pressure fuel pipe,
in order to prevent the fuel outlet of the fuel injection
pump from follow-up rotation). Remove the high
pressure fuel pipe and install the high pressure fuel pipe
protective sleeve;
b. Remove the fuel injector return hose.
c. Remove the fixing bolts of fuel injector pressure plate,
remove the fuel injector body along with its support,
and install the fuel injector protective sleeve.
4. Disassemble the fuel-gas separator
subassembly
a. Remove the crankshaft breathe hose and fuel-gas
separator return hose.
b. Disassemble the fixing bolts of fuel-gas separator.
c. Remove the fuel-gas separator.

Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
21
d. Remove the fixing bolts of fuel-gas separator housing
and take out the fuel-gas separator filter element. Clean
the fuel-gas separator housing, check the state of filter
element, and when necessary replace the filter element.
e. Disassemble the fixing bolts of fuel-gas separator
bracket and remove the fuel-gas separator bracket.
4. Disassemble the intake manifold and
other peripheral accessories.