When the excavator is repaired and inspected, fuel will flow out, so prepare an oil pan of about 20L for receiving the fuel. When measuring, park the machine on a level ground and lower the working device to the ground.
1. Measure the oil return of the oil supply pump
① Open the engine cover, as shown in Figure 2-23, and disconnect the oil return hose of the oil supply pump. The oil return hose is connected by a quick connector.
Figure 2-23 Disconnect the oil return hose of the oil supply pump
② Install the connector G3 and the cap nut of the experimental instrument assembly G1 to the oil return hose to prevent fuel from flowing out.
③ As shown in Figure 2-24, connect the test hose of the tester component G1 to the fuel supply pump. Level the test hose to make its pipeline smooth, and put its end into the oil pan (for oil connection).
1—Nut; 2—Test hose; 3—G3 connector Figure 2-24 Connect the test hose of the tester assembly G1 to the fuel supply pump
④ Run the engine at low idle speed, measure the oil return within 1 min with a graduated cylinder G4, as shown in Figure 2-25. If the oil return volume of the fuel supply pump does not exceed 1 000 ml/min at low idle speed and does not exceed 140 ml/min at startup, it is regarded as normal.
If the engine cannot be started, the fuel pressure can be measured when starting the engine with the starter. However, in order to protect the starter, do not use the starter to start the engine more than 20so
⑤ After measuring, remove the measuring tool and reinstall the removed parts.
After measuring the oil leakage of the pressure limiter, remove the measuring tool and reinstall the removed parts to their original positions.
There is no need to install the removed parts when the fuel injector leaks, and keep the end of the hose in the oil pan.
2. Measure the leakage of the pressure limiter
① Open the engine hood and disconnect the oil return hose of the pressure limiter as shown in Figure 2-26. Install the sealing washer on the connector bolt.
② As shown in Figure 2-27, install the removed connector bolt and the end cap nut of the tester assembly G1 to the oil return hose to prevent fuel from flowing out.
Figure 2-27 Install the removed connector bolt and the end cap nut of the tester assembly G1 to the oil return hose
③ Install the connector G3 to the common oil tank, and connect the test hose of the tester assembly G1. Lay down the test hose to make its pipeline smooth, and put its end into the oil pan (for receiving oil).
④ Run the engine at a low idle speed, and measure the oil return within 1 min with a graduated cylinder G4. If the leakage of the pressure limiter is Oml (no leakage) at low idle speed, it is considered normal.
⑤ After measuring, remove the measuring tool and reinstall the removed parts.
3. Measure the oil return of the injector
When connecting the oil return hose of the pressure limiter, the oil leakage of the fuel injector can be measured. Before measuring the oil leakage of the fuel injector, ensure that the oil leakage of the pressure limiter is normal.
① Measure the oil return speed of the oil supply pump, and set the oil supply pump for testing. During the measurement of the fuel return speed of the fuel injector, the fuel returning from the fuel supply pump will flow out. Therefore, keep the end of the test hose in the oil pan.
② As shown in Figure 2-28, disconnect the oil return hose of the oil return device. Install the sealing washer on the oil return hose.
Figure 2-28 Disconnect the oil return hose of the oil return device
③ As shown in Figure 2-29, install the connector bolt of pipe joint G2 to replace the removed connector bolt, and connect the test hose. Level the test hose to make its pipeline unblocked, and put its end into the oil pan (for oil connection).
1—Test hose; 2—Connector bolt Figure 2-29 Install the connector bolt of pipe joint G2
The shape of the parts shown in Figure 2-29, PC200 and PC220-8 are not exactly the same (for reference only).
④ Run the engine at low idle speed and measure the oil return within 1 min with a graduated cylinder G4. If the fuel return volume of the fuel injector does not exceed 180ml/min at low idling speed and does not exceed 90ml/min at startup, it is regarded as normal.
If the engine cannot be started, measure the fuel pressure when starting the engine with the starter. However, in order to protect the starter, do not use the starter to start the engine for more than 20 seconds.
⑤ After measuring, remove the measuring tool and reinstall the removed parts.
