JAC HFC4DA1-2C engine. Instruction — part 3

Maintenance instruction for sunray hfc4da1-2c china-IV diesel engines

34

s.

Measure the outside diameter of connecting rod journal
and the inside diameter of bush bore of connecting rod
fitted with bush.

Calculate the clearance between main journal of crankshaft
and the main bush bore of crankshaft: The difference
between the diameter of main journal and the inside
diameter of crankshaft main bush bore measured above is
the fitting clearance. The wear limit shall not exceed
0.11mm.

Notice: While measuring the inside diameter of
crankshaft main bush bore, install the bearing cap and
bush onto the bearing block and tighten the bolts to
specified torque. Use an inside multimeter to measure
the inside diameter.

Calculate the clearance between crankshaft connecting rod
journal and connecting rod bush bore: The difference
between the diameter of connecting rod journal and the
inside diameter of connecting rod bush bore measured
above is the fitting clearance. The wear limit shall not
exceed 0.10mm.

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Section II Assembly of Engine

I. Basic Technical Requirements for Assembly

The assembly of the engine is one important step for service of the engine. The service performance of the engine is
closely related to the assembly accuracy, assembly technical requirements, and the assembly quality. Make sure to pay
attention to following items:

Before the assembly, make sure to thoroughly clean and thoroughly blow dry all parts and components. All friction
surfaces of the parts with relative movement are applied with lubricating oil (grade CE diesel engine oil or above).
Carefully remove all oil dirt and carbon deposit, till the base metal is exposed. Never use electric wire brush to clean
the sealing surfaces of any sealing gasket. Remove the residues from all used sealing gaskets. It’s absolutely
prohibited to use wire brush to clean the piston.

a. Remove the carbon deposit, oil dirt, and water scale and clean all lubricating oil pipes and pipelines.

b. Check the wear state of valve, push rod, and rocker arm contact surfaces and when necessary repair or replace.

c. Check the wear state of piston rings, cylinder sleeves, connecting rod small end bushes, and connecting rod bushes
and when necessary replace.

d. Check the wear state of main bushes and thrust plates.

e. Check the wear state of engagement surfaces of transmission mechanism and drive gear and measure the
engagement clearance and when necessary repair or replace.

f．Check the wear state of intake and exhaust valves and intake and exhaust valve seats and repair, grind, and test the
leakage and when necessary replace.

g．Check the mist injection state of the fuel injector and when necessary grind or replace the fuel injector coupler.
While installing the used fuel injector, clean the carbon deposit with ultrasonic and do not wipe with silk or scrape
with knife, in order to prevent damaging the injector nozzle and blocking the injector orifice.

h. Check the engine oil pump and disassemble for checking or measure the wearing parts and adjust accordingly.

i. Check the cylinder gasket and intake and exhaust pipe gaskets and replace any damaged or failed gasket.

j. Check the alternator and starter, clean all parts and bearings, blow dry and apply new lubricating grease, and check
the wear state of starter gear and check the transmission mechanism for flexible functioning.

k. Check and clean the turbocharger.

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II. Illustration for Assembly of Engine

1. Install the piston cooling fuel injector
subassembly.

a. Install the piston cooling fuel injector subassembly:

Install the piston cooling fuel injector subassembly
onto the engine block;

b. Tighten the hexagon socket screws to 12.5±2.5N.m;

2. Install the crankshaft, thrust plates,
and main bearing caps.

a. Install the upper and lower main bushes: Align the

stop opening of upper main bush with the slip groove
of the main bearing block bore of engine block and
push 5 upper main bushes to place;

Notice: While installing the main bushes, make
sure to differentiate the upper and lower bushes,
of which the upper bush has oil grooves and the
lower bush has not. Do not install the bushes
reversely.

a.

Apply an appropriate amount of clean engine oil onto
the upper bearing bush;

b. Lift up and place the crankshaft onto the engine

block.

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c. Install the crankshaft thrust plates to the 3

rd

main

journal portion (The surface with oil groove faces to
crankshaft thrust surface and the oil groove shall be
sprayed with lubricating oil).

d. Spray oil to the main journal portion and install the

1~4 main bearing caps of crankshaft as per the
marked sequence. The arrow markings on the bearing
caps shall face to the front of the engine.

e. Apply the liquid sealant onto the fitting surface

between 5

th

bearing cap and cylinder block and install

the 5

th

bearing cap * text: Notice: 1) Before applying

the sealant, the fitting surface of main bearing cap
shall be thoroughly free of any engine oil; 2) Never
block the cylinder threaded holes and bearings by the
sealant.

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f. Apply engine oil onto the threads of main bearing cap

bolts, install into the main bearing caps, and tighten
the bolts to 170 N.m torque as per the specified
sequence. Tighten to 20 N·m for the 1

st

step, to 120

N·m for the 2

nd

step, and 170 N·m for the 3

rd

step.

Tightening sequence: (From center to two sides)

8415 9

7326 10

g. Adhere the magnetic dial gauge onto the cylinder

block, position the pointer of the dial gauge to the
rear end face of crankshaft, and use a straight
screwdriver to pry lightly the crankshaft to check the
axial clearance of crankshaft (or push the crankshaft
left and right and measure with feeler gauge). If the
thrust clearance is out of the limit, replace the thrust
bearings in pair. Standard value: 0.040mm-0.201mm;
Limit: 0.30mm

h. Rotate the crankshaft and check for flexible rotation

and presence of noise. Alternatively, use a digital
wrench to measure the net torque of crankshaft, listen
for presence of noise, and check whether the torque is
≤6N.m.

a

Insert the lubricated tappets in turn into the tappet
holes.

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b. Install the tappet anti-drop tool.

3. Install the piston connecting rod
assembly.

a. Spray one film of oil onto the cylinder bore.

b. Spray oil onto the piston skirt, install the piston into

the piston taper sleeve, insert into the cylinder bore,

and use nylon bar and guide jig to install the piston.

Notice: (The connecting rod and bolts shall not

come into contact with the cylinder bore and the

large end bore of connecting rod shall be

orthometric with the crankshaft journal.)

c. After installing the large end cap of the connecting

rod, tighten the large end nut of connecting rod to

20N· m and 85N· m by two times.

d. Use a feeler gauge to check the side play of large end

of connecting rod. The side play range for large end

of connecting rod: 0.175-0.29mm.

e. After the installation of pistons for 1

st

and 4

th

cylinders, rotate the crankshaft for 180º and install

the pistons for 2

nd

and 3

rd

cylinders.

Maintenance instruction for sunray hfc4da1-2c china-IV diesel engines

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4. Install the timing gear and related
accessories.

a. Insert the lubricated tappets in turn into the tappet

holes.

b. Install the water manifold (The water manifold is

paralleling with the cylinder block)

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c. Spray oil to the crankshaft gear and then install.

d. Install the gasket of timing gear chamber.

e. Install the timing gear chamber and idler gear lining

plate and pre-tighten the fixing bolts.

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f. Spray lubricating oil onto the camshaft bush, add

lubricating oil to the head of tappet, and spray
lubricating oil onto the camshaft subassembly.

g. Install the camshaft (with the bottom facing upward

and the left facing forward).

h. Tighten the fixing bolt subassembly of camshaft

thrust plate to 25±5N.m.

i. Install the engine oil pump outlet pipe subassembly

and engine oil pump assembly with strainer.

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j. Install the idler gear shafts A and C onto the idler

gear lining plate and use nylon bar for idler gear shaft
to lightly knock into the idler gear lining plate.

k. Apply oil onto the surface of idler gear C bush and

lightly rotate into the idler gear shaft C. Then, apply
oil onto the surface of idler gear A bush and use
nylon bar to lightly knock into the idler gear shaft A.
Take caution to apply the force lightly and uniformly,
in order to prevent the abnormal wear of bush.

l. While installing the idler gear A, take caution to

adjust the installation position of idler gear A and "2
2” position of camshaft gear as per the “1 1” marking
of crankshaft gear. (Timing photo)

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m. Apply oil onto the surface of idler gear B bush and

lightly rotate into the idler gear shaft B. In event of
difficult installation, slightly rotate the crankshaft to
help installation.

n.

Use the hexagon flange bolts to install the idler gear
pressure plates A, B, and C onto the idler gear shaft
and tighten the fixing bolts of pressure plate and
fixing bolts of idler gear lining plate to 25±5N. m
torque.

5. Install the oil sump.

a. Use a scraper to remove the excessive portion of the

gear chamber.

b. Install and pre-tighten the stud * 12 of oil sump.

Maintenance instruction for sunray hfc4da1-2c china-IV diesel engines

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c. Apply sealant to the lower end face of timing gear

chamber and the lower rear end of engine block.

d. Install the oil sump gasket.

e. Apply the sealant for the second time to both sides of

oil sump gasket.

f.

Install the oil sump assembly with oil drainage screw
plug and use nylon bar to lightly knock the oil sump
to ensure the steady installation of oil sump.

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g. As per the specified sequence, tighten the fixing bolts

*10 of oil sump and the fixing nuts * 12 of oil sump
to 23.5±3.5N.m torque.

h. Use a cotton cloth to wipe away excessive sealant.

5. Install the timing gear chamber.

i. Pre-install the flange O-ring of fuel injection pump

onto the fuel injection pump.

j. Place the fuel injection pump into installation

position, install and pre-tighten the hexagon socket

fixing bolts of fuel injection pump, and install the

fuel injection pump gear and fixing nuts of fuel

injection pump.

k. Tighten large fixing nuts of fuel injection pump to

70±5 N·m and tighten hexagon socket fixing bolts of

fuel injection pump to 30±5 N·m.

l. Install the water pump O-ring onto the water pump

and use hand to rotate the impeller for two turns to

ensure that the water pump rotates flexibly.

m. Install the water pump assembly to the gear chamber.

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n. Install and tighten the bolts and nuts of water pump in

diagonal manner to 25±5N.m.

o. Install the timing gear chamber cover subassembly

and attach and tighten the fixing bolts of gear

chamber cover to 20±5 N.m.

p. Torque for hexagon socket fixing bolt: 60±10 N.m.

q. Install the damping pulley and attach and tighten the

fixing bolts of damping pulley to 210±15 N·m.

6. Install the cylinder head and related
accessories.

a. Check whether the upper surface of cylinder block is

normal and the cylinder gasket is normal and install

the cylinder gasket.

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b. Install the cylinder head onto the cylinder block.

c. Immerse the thread portion of cylinder head bolts into

oil and then install into the cylinder head and

pre-tighten.

d. Tighten the cylinder head bolts by steps from the

center to two sides as per the specified sequence:

65N.m→85N.m→105N.m

e. Install the thermostat housing and water outlet

assembly and tighten the fixing bolts and hexagon

socket fixing bolts.

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7. Install the intake manifold and
related accessories.

a. Use hexagon flange bolts to fix the fuel rail bracket

onto the cylinder block and tighten to 37.5±9.5N.m.

b. Use hexagon flange bolts to install the fuel rail

assembly with rail pressure sensor onto the fuel rail

bracket and tighten to 25±5N.m.

c. Install the intake manifold gasket.

d. Insert the oil dipstick into the cylinder block and

tighten the fixing bolts and nuts of intake manifold as

per the specified sequence.