Komatsu BR380JG-1E0, Shop Manual, Page: 267 / 841

30 Testing and adjusting SEN02303-00
BR380JG-1E0
9
Adjusting valve clearance 1
a
Measuring tools for valve clearance
k
Stop the machine on a level ground.
a
Measure the valve clearance under the follow-
ing condition.
q
Engine coolant temperature: Normal tem-
perature
1. Open the engine hood and remove the bracket
for the fan guard and engine step.
2. Remove cylinder head cover (1).
a
Since the breather connector on the rear
side of the cylinder head cover is con-
nected to the flywheel housing through the
O-ring, pull it together with the cylinder
head cover.
3. Remove plug (2) from the top of the starting
motor and insert gear
C1 .
4. Rotate the crankshaft forward with gear C1
and set wide slit (b) of the rotation sensor ring
to projection top (a) of front cover.
a
Projection top (a) must be within the range
of wide slit (b) when it is seen from the fan
side.
a
If you can see the yellow marks of projec-
tion top (a) and wide slit (b), you may set
them to each other.
k
When the crankshaft is set as above,
the piston in the No. 1 or No. 6 cylinder
is not set to the compression top dead
center (TDC). Take care.
5. Check the movement of the rocker arm of the
No. 1 cylinder to judge the valve to be
adjusted.
a
If you can move the rocker arms of air
intake valves (IN) with the hand by the
valve clearance, adjust the valves marked
with
Q
in the valve arrangement drawing.
a
If you can move the rocker arms of
exhaust valves (EX) with the hand by the
valve clearance, adjust the valves marked
with
q
in the valve arrangement drawing.
a
Valve arrangement drawing
Symbol Part No. Part name
C
1 795-799-1131 Gear
2
Commercially
available
Clearance gauge