Measuring Compression Pressure - Komatsu PC130-7 Shop Manual

TESTING AND ADJUSTING
MEASURING COMPRESSION
PRESSURE
a Measuring instruments for compression pressure
Symbol Part No.
795-502-1205
C 795-502-1370
6204-11-3880
a When measuring the compression pressure,
take care not to burn yourself on the exhaust
manifold, muffler, etc. or get caught in a rotating
part.
1. Adjust the valve clearance.
a See Adjusting valve clearance.
2. Warm up the engine until the engine oil tempera-
ture is 40 – 60°C.
3. Prepare for measuring the engine speed.
a See Testing and adjusting engine speed.
4. Open the engine hood and remove nozzle holder
(1) of the cylinder to measure the compression
pressure.
5. Install adapter [1] of compression gauge C to the
mounting part of the nozzle holder and connect
gauge [2].
a Install the gasket to the end of the adapter.
a Secure the adapter with the clamping holder
3 Mounting bolt: 39.2 – 49 Nm {4 – 5 kgm} and mounting bolt for the nozzle holder.
PC130-7
Part name
Compression gauge
Adapter
Gasket

MEASURING COMPRESSION PRESSURE

6. Remove governor spring (2).
7. Put governor lever (3) of the fuel injection pump
to the STOP side stopper and fix it.
8. Crank the engine with the starting motor and
measure the compression pressure.
a Read the compression gauge when its
pointer is stabilized.
a When measuring the compression pressure,
measure the engine speed, too, and check
that it is in the measurement condition range.
9. After finishing measurement, remove the mea-
suring instruments and return the removed parts.
a Check that the fulcrum of the clamping
holder for the nozzle holder is seated on the
cylinder head, and then tighten the mounting
3 Mounting bolt: 39.2 – 49 Nm {4 – 5 kgm}
bolt.
20-109
(1)