Testing And Adjusting Valve Clearance - Komatsu PC88MR-10 Shop Manual

30 Testing and adjusting
Engine and cooling system

Testing and adjusting valve clearance

a Tools for testing and adjusting
Sym-
Part No.
bol
Commercially
C
available
Place the machine on a level ground and
lower the work equipment to the ground.
Turn the battery disconnect switch to OFF
position, and remove the key.
a Check this item under the following conditions.
Coolant temperature: Normal temperature
Testing
(PC88MR-A700-361-K-00-A)
1. Remove cylinder head cover. For details, see
Disassembly and assembly, "Removal and
installation of injector assembly".
2. Remove undercover (11) and turn the crankshaft
from the opening at the bottom of the crankshaft
pulley.
3. Rotate crankshaft pulley (12) forward and match
compression top dead center mark (a) to large
slit (b) of ring (13).
a Rotate the crankshaft by using the crankshaft
pulley bolt (2) (width across flats: 27 mm).
a At the compression top dead center, the
rocker arm of No.1 cylinder can be moved by
valve clearance with hands. If the rocker arm
does not move, cylinder is not at the
compression top dead center, so rotate the
crankshaft further 1 turn.
30-10
Part name
Feeler gauge
(PC88MR-A700-360-K-00-A)
4. Check the valve clearances marked with q in
the valve arrangement drawing.
5. Insert feeler gauge C into the clearance between
rocker arm (14) and crosshead (15) to check the
valve clearance.
a For standard values, see "Standard value
table for engine".
6. After finishing the test, remove the testing tools,
and restore the machine.
Adjusting
(PC88MR-A700-27D-K-00-A)
After testing, adjust the valve clearance according
to the following procedure, if necessary.
1. While fixing adjustment screw (16), loosen lock
nut (17).
2. Insert feeler gauge C in the clearance between
rocker arm (14) and crosshead (15) and adjust
the valve clearance with adjustment screw (16).
PC88MR-10