Testing Compression Pressure - Komatsu PC200-8M0 Shop Manual

101 Testing and adjusting, Part 1

Testing compression pressure

Testing compression pressure

a Measuring tools for compression pressure
Symbol Part No.
1 795-799-6700 Puller
2 795-502-1590 Gauge assembly
3 795-790-4410 Adapter
C
4 6754-11-3130
Commercially
5
available
k
Be careful not to touch the exhaust mani-
fold or muffler, which may get you burnt, or
get caught in a rotating part when checking
compression pressure.
k
Keep the cable disconnected from the nega-
tive ( ) battery terminal.
-
a Measure the compression pressure after the
engine is warmed up.
(Engine oil temperature: 40 to 60°C)
1. Open the engine hood and remove the belt
guard at the top of the air conditioner compres-
sor.
2. Disconnect three connectors (2) and two
bands (3) from wiring harness (1), and sepa-
rate wiring harness (1) from the head cover.
a Since the connector has a lock stopper,
press down the stopper with your finger
and pull the connectors apart. At that time,
support the gasket with your hand not to
move.
3. Remove five head cover mounting bolts (4).
a After loosening the bolts, hold the head
cover and blow off the sludge and foreign
matters attached around with air so that
they do not get into the head cover mount-
ing section.
4. Remove head cover (5).
a Take care not to hit the cover against
nearby parts.
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.
PC200, 200LC, 220, 220LC-8M0
Part Name
Gasket
Hose inside diameter:
approx. 15 mm
1
5. Disconnect fuel high-pressure tube (6).
a When measuring compression pressure,
fuel spurts from the disconnected portion
on the common rail side. Therefore, con-
nect hose C5 and drain the fuel into a con-
tainer.
k
Do not make bending modification of
the high-pressure pipes to be used.
6. Loosen injector terminal nut (7), and remove
the terminal from the injector.
7. Set the piston in the cylinder to be checked to
the compression top dead center.
a See "Adjusting valve clearance".
8. Remove rocker arm assembly (8).
SEN06127-00
13
30-101