Use Kobelco excavator maintenance compression pressure measuring tool to test cylinder pressure. During the test, the machine should be parked on a level ground and the working device should be lowered to the ground. Measure the cylinder compression pressure under the condition of the oil temperature of 40~60°C.
① Open the engine cover and remove the cylinder head cover. Since the breather connector on the rear side of the cylinder head cover is connected to the flywheel housing through the O-ring, the breather connector and the cylinder head cover must be unplugged together.
Remove the cylinder cover
② Remove the mounting bolts of the rocker arm assembly on the exhaust side, and then remove the rocker arm assembly. When removing the injector, there is no need to remove the rocker arm assembly on the intake side.
③ Remove the fuel pipe shown in Figure 2-12, and then remove the inlet connector in the cylinder head. The inlet connector connects the fuel pipe to the fuel injector.
④ Disconnect the injector wire harness. Remove the injector with tool C2.
1T Jia oiler clamp; 2-1 and Ul device; 3—inlet connector; mountain pipeline Figure 2-13 inlet connector
⑤ Use the injector clamp to install the pipe joint to the injector installation part and connect the air pressure gauge. Be sure to correctly install the gasket to the end of the pipe joint.
Injector clamp mounting bolt: tighten the torque (3.5±0.35) N·m for the first time, and tighten it again at a tightening angle of (75 ±5) ° for the second time.
During installation, if a small amount of engine oil is applied to the connection between the pipe joint and the instrument, it is difficult for air to leak.
⑥ Install the rocker arm assembly on the exhaust side and adjust the valve clearance.
⑦ Disconnect the CE03 connector of the engine controller. If the connector is not disconnected, the engine will start during the measurement, which is dangerous. Since the CE03 connector is a part of the engine power circuit, cover the connector on the side of the machine with a vinyl plate or the like to prevent leakage and ground faults.
1—Barometer; 2—Rocker arm assembly; 3—Pipe joint
Connect barometer
⑧ Start the engine and measure the compression pressure. When the pointer is stable, read the meter reading.
⑨ After the measurement is completed, remove the measurement tool and reinstall the removed parts. Follow the steps below to install the injector and inlet connector.
① Apply new engine oil to the O-rings of the injector and cylinder head.
② Install the fuel injector using the fuel inlet hole that is guided to the intake manifold.
③ Install the injector clamp and tighten the mounting bolts with 3 to 4 threads.
④ Install the inlet connector and temporarily tighten the inlet connector holder.
⑤ Tighten the mounting bolts of the injector clamp firmly. The tightening torque of the injector clamp mounting bolt is (8±0.8) N·m.
⑥ Tighten the inlet connector holder firmly. The tightening torque of the inlet connector holder is (50±5) N·m. Tighten the bolts and nuts other than the fuel injector and inlet connector to the following torque.
Injector wire harness nut: (1.5 ± 0.25) N ? mo
Fuel pipe bushing nut: (35±3.5)N·m.
Mounting bolt of rocker arm assembly: (36±6)N·m.
For the method of adjusting the valve clearance, see "4. Adjusting the valve clearance". Tightening torque of cylinder head mounting bolts: (24±4)N·m.
