JAC HFC4DA1-2C engine. Service Manual — part 2

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.

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

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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.

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

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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

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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.

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

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a.

Disassemble the fixing bolts of power steering pump
and remove the power steering pump.

b.

Check the power steering pump for presence of oil
leakage and check the belt pulley of power steering
pump for presence of wear;

c.

Remove the EGR valve.

d.

Remove the fixing bolts of air intake pipe bracket.

e.

Remove the air intake pipe bracket and fuel-gas
separator bracket.

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

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f.

Remove the fuel rail and rail pressure sensor assembly
and the rail bracket and install the fuel pressure rail
protective sleeve;

g.

Disassemble

h.

Disassemble the fixing bolts of oil dipstick fixing
sleeve and disassemble the oil dipstick conduit.

i.

Disassemble the fixing bolts and nuts of intake
manifold. Remove the intake manifold;

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

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j.

Remove the fixing bolts of compressor bracket and
remove the compressor bracket;

k.

Remove the bypass rubber pipe, remove the thermostat
housing and water outlet assembly; Disassemble the
fixing bolts of thermostat housing and remove the
thermostat housing.

l.

Remove the fixing bolts of cylinder head shield and
remove the cylinder head shield;

m. Remove the bolts and nuts of rocker arm support as per

specified sequence and remove the rocker arm
assembly. Sequence: 4-1-3-2

n.

Notice: The failure to loosen the bolts of rocker arm
support as per the specified sequence will damage the
rockshaft*.

o.

Take out the push rod;

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

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p.

Remove the cylinder head bolts by several times as per
the specified sequence (front circle drawing method).

q.

The failure to disassemble by several times as per

specified sequence will damage the cylinder head and
impair the deflection of lower surface of cylinder
head*.

r.

Remove the damping pulley.

Remove the fixing bolts of water pump, remove the
water pump, and check the water pump blades for
presence of cracking and corrosion and check the
blade shaft for presence of wear.

s.

Disassemble the fixing bolts of timing gear chamber
cover and remove the timing gear chamber cover and
cover gasket.

t.

Remove the engine left bracket.

u.

Loosen the bypass rubber hose clamp, loosen the
fixing bolts of water inlet pipe weldment, and remove
the water inlet pipe weldment.

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

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v.

Disassemble the fixing bolts of engine oil filter and
remove the engine oil filter.

w. Use an open-end wrench to disassemble the engine oil

pressure connector and remove the connector and
lubricating oil pipe.

x.

Loosen the fixing nuts of fuel injection pump gear,
remove the hexagon socket fixing bolts of fuel
injection pump and the fixing nuts of fuel injection
pump gear, knock lightly the fuel injection pump gear
shaft with rubber hammer, remove the fuel injection
pump and fuel injection pump gear, and install the fuel
injection pump protective sleeve. The fuel injection
pump shall be insulated from the air and dust.

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

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y.

Remove the fixing bolts of idler gear pressure plate
and remove the idler gear pressure plate, idler gear, and
idler gear shaft.

z.

Remove the fixing bolts and fixing nuts of oil sump by
one time as per the specified sequence and remove the
oil sump.

aa. Remove the fixing bolts of engine oil pump and pull

out the engine oil pump.

bb. Remove the fixing bolts of camshaft.

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

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cc. Pull out the camshaft.

dd. Remove the nuts of connecting rod large end as per

specified sequence and use piston installation tool to
push out the piston. Position the piston orderly.
Visually observe each piston for presence of
cracking, scratch, and other excessive wear.

ee. Disassemble the fixing bolts of timing gear chamber

and the fixing bolts of idler gear lining plate and
remove the idler gear lining plate.

ff. Use a rubber hammer to knock lightly the timing

gear chamber from both sides to remove the timing
gear chamber.

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

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gg. Take out the crankshaft timing gear.

hh. Rotate the bolts of master bearing cap as per

specified sequence to pull out the bolts of master
bearing cap and remove the main shaft bushes
(Position the main shaft bushes orderly).

ii. Overturn the crankshaft to take out the crankshaft

thrust plate and remove the crankshaft and the
crankshaft lower bushes.

jj. Check the wear state of the crankshaft thrust plates.

kk. Disassemble the piston cooling fuel injection pipe

subassembly.

5. Check the parts.

a.

Check the lower surface of the cylinder head. Strict
planeness tolerance is required for the fitting surface of
the intake and exhaust branch pipes.

b.

These surfaces can be repaired by grinding. If the
surface planeness is out of the specified tolerance,
grind the surface to meet the technical requirements. If
the planeness is excessively out of the technical
requirements, replace the cylinder head.

Deflection of cylinder head lower surface 0.05

or

less

Limit 0.20

Cylinder head height Standard value 92 Limit
91.55

c.

Use ruler and feeler gauge to measure the deflection of
fitting surface between exhaust branch pipe and

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

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cylinder head.

If the measurement is between limit and standard
value, re-grind the fitting surface between exhaust
branch pipe and cylinder head.

If the measurement is out of the specified limit, make
sure to replace the branch pipe.

d.

Use a multimeter to measure the outside diameter of
piston at the position 73.9mm reach from the piston
crown.

Standard value:

A: 92.971~92.980mm

B: 92.981~92.990mm

C: 92.991~93.000mm

D: 93.001~93.010mm

e.

Use an inside micrometer to measure:

Standard value for inside diameter of cylinder bore
fitted with cylinder sleeve:

A:93.021~93.030mm

B:93.031~93.040mm

C:93.041~93.050mm

D:93.051~93.060mm

f.

Subtract the inside diameter of cylinder bore from the
outside diameter of piston to obtain the piston
clearance. The clearance range of piston:
0.041~0.059mm.

If the piston clearance is out of the specified range,
check and replace the cylinder sleeve or piston,
depending on the cylinder bore grouping and the
outside diameter of piston.

(The second line of the stamped code at the rear end
of lower surface of new cylinder block indicates the
inside diameter group of the cylinder bore).

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

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g.

Measure the cam height of the camshaft. The standard
value is 42.02±0.05mm and the limit is 41.65mm. If
the measurement is out of the limit, make sure to
replace the camshaft.

h.

Use a multimeter to measure the outside diameter of
each camshaft journal. If any measurement is out of
the limit, replace the camshaft. The standard value for
outside diameter of journal is 49.945-49.975mm and
the limit is 49.60mm. If any measurement is out of the
limit, replace the camshaft.

i.

Use a feeler gauge to measure the axial run-out
clearance of the camshaft. The axial run-out clearance
of camshaft is 0.05~0.114mm.

j.

Use a multimeter to measure the outside diameter of
valve stem. If the measurement is less than the
specified limit, make sure to replace the valve and
valve guide in pair.

(Intake valve: 7.946-7.961mm; limit: 7.880mm)

(Exhaust valve: 7.921-7.936mm; limit: 7.850mm)

k.

Use a multimeter to measure the inside diameter of
valve guide and subtract the outside diameter of valve
stem from the measurement to obtain the valve guide
clearance. If the clearance obtained is out of specified
limit, make sure to replace the valve and valve guide in
pair.

(Limit of intake valve guide clearance: 0.200mm)

(Limit of exhaust valve guide clearance: 0.250mm)

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

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l.

Measure the free height of valve spring. If the
measurement is out of specified limit, make sure to
replace the spring.

The standard value is 0.05mm or less and the limit is
0.20mm.

m. Use a feeler gauge to measure the clearance between

piston ring groove and piston ring.

If the clearance between piston ring groove and piston
ring is out of specified limit, make sure to replace the
piston.

n.

Use a feeler gauge to measure the opening gap of
piston ring.

If the opening gap of the piston ring is out of specified
limit, make sure to replace the piston.

o.

Install the steel-strip oil ring.

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

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p.

Install the oil ring bush ring.

q.

Use a piston ring expander to install the 2

nd

compression ring and the 1

st

compression ring. While

installing the compression rings, face upward the
marking N (The lip of 2

nd

compression ring shall face

downward).

The overlap position of oil control ring cushion spring
and the opening of oil control ring steel strip shall be
180º away from each other and shall be 90º away from
the 2nd compression ring.

r.

Measure the outside diameter of main journal and the
inside diameter of main shaft bore.

Illustration of opening directions for

piston rings

Forward marking

Compression

ring

Overlap of oil

control ring

cushion spring

Opening of oil control
ring steel strip

Main thrust face

Auxiliary
thrust face

Compressi
on ring

Piston pin direction