Engine JAC HFC4DA1-2C. Manual — part 7

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).