Komatsu 82E Series - Page 86

82E-5 – 98E-5 SERIES 4-17
4. DISASSEMBLY, INSPECTION AND REASSEMBLY OF ENGINES
[NOTICE]
1) When a diaphragm is damaged, pressure control inside the crankcase becomes insufficient, and
troubles occur. When the internal pressure of the crankcase decreases too much due to the damage of
a spring, much blowby gas containing oil is reduced in intake air system, and it may cause the
combustion defect by the early dirt of the intake valve or the urgent rotation of the engine by the oil
burning.
When pressure progresses in the crank case too much due to the wrong operation of the diaphragm
and so on, it is considered that oil leakage from the joint of an oil pan, an oil seal and so on will occur.
When a diaphragm is damaged, blowby is discharged from the breathing hole on the side of diaphragm
cover, and not reduced in the intake manifold. Therefore, be careful of the diaphragm trouble.
2) At lubricating oil replacement or lube oil supply
The amount of lubricating oil isn't to be beyond the standard upper limit (in the engine horizontality, the
upper limit mark of the dip stick). Since the blowby gas reductor is adopted, be careful that the amount
of oil mist may be inducted in the combustion chamber and the oil hammer sometimes may occur, when
the lubricating oil quantity is beyond the upper limit or an engine is operated beyond the allowable max-
imum angle of an engine.
[Reassembly]
• Replace the diaphragm with new one, when it is damaged.
Point 7
[Disassemble]
• Keep the removed push rods by attaching tags
showing corresponding cylinder Nos.
[Reassemble]
• Always apply oil to the contact portions of the
push rods and clearance adjusting screws.
Point 8
[Disassemble]
• Loosen the cylinder head bolts in two steps in
the illustrated order.
• Place the cylinder head ass’y on a paper board
to prevent the combustion face from any dam-
age.
[Reassemble]
• Remove the head gasket with a new one.
• Uniformly install the head bolts manually after
applying oil on the threaded and seat portions.
• They shall be tightened in two steps in the
reverse of the order for disassembly.
Tightening torque Nm {kgm}
3D82AE
(S)3D84E
(S)4D84E
3D88E
4D88E
4D94LE
(S)4D98E
First
step
30.0 – 34.0
{3.1 – 3.5}
41.1 – 46.9
{4.2 – 4.8}
49.0 – 58.8
{5.0 – 6.0}
Second
step
61.7 – 65.7
{6.3 – 6.7}
85.3 – 91.1
{8.7 – 9.3}
103.1 – 112.9
{10.5 – 11.5}