Older excavators were always confused by the common failures of exhaust pipes emitting black smoke. In addition to the exhaust pipes emitting black smoke from the exhaust pipes that can not tell the time and address of the four seasons, the maintenance can also be solved. It is time-consuming and laborious, and a lot of money is spent every year on maintenance alone.
The main reaction of the Caterpillar M315D2 engine is that the engine emits black smoke when the equipment is working. The black smoke from the exhaust pipe is relatively light when the diesel engine is running at medium speed. The black smoke from the exhaust pipe is quite large when it is running at high speed, although there is no delay. The project is under construction, but I feel uneasy from beginning to end. Let’s take a look at the entire repair process of this Caterpillar M315D2 in the excavator repair shop.
Analysis of common faults
1. The air filter element is dirty and clogged, which leads to insufficient air intake, which causes the exhaust pipe to emit black smoke.
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2. The quality of the diesel engine charged by the equipment is not very good, resulting in incomplete ignition.
3. The hydraulic machine is faulty, the main overflow working pressure is too high, and the main valve relay and controller are common faults.
4. Common failures of turbochargers cause the working pressure of the air inlet to decrease.
5. Common failures of diesel engine high pressure water pump and fuel injection pump cause poor diesel engine atomization.
Common fault check
1. The inspection of the filter element is very convenient and quick. First open the rear cover of the air filter element, and check that the air filter element is only slightly dirty. After cleaning with compressed air, reinstall it. After debugging, the common faults still remain. Clear the air filter element is common malfunction.
2. Open the oil cap, take a sample of the diesel engine, and observe the cleanliness of the diesel engine. In addition, the engine owner shows that the fuel usually added is guaranteed, and the quality problems of the diesel engine 名媛直播 are basically eliminated. In this way, check the fuel bottom pressure fuel pipe, replace the fuel filter element, remove the gas, and debug the common faults.
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3. Check that the overflow working pressure of the main valve of the hydraulic press is 345bar, and the working pressure is normal. The original working pressure at the standby speed is also around 40bar, everything is normal. When rotating at a high speed without a posture, there will be black smoke from the exhaust pipe, so this can eliminate common faults at the hydraulic press level.
4. Turn on the turbocharger air inlet and rotate the centrifugal impeller by hand. The centrifugal impeller can be easily rotated without sweeping. The rolling bearing volume is within the normal range, and there is no car oil leakage. Clear the turbocharger. Common malfunctions.
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5. When it was adjusted to high-speed rotation to emit black smoke from the exhaust pipe, the cylinder cut test was carried out. After the cylinder was cut one by one, there was no occurrence of a certain cylinder's poor work which caused the exhaust pipe to emit black smoke. Eliminate the poor atomization factor of the fuel injection pump.
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After clearing around, people suspect that the diesel engine high-pressure water pump has common faults. The high-pressure diesel pump was disassembled, and the pump was calibrated. After the test on the test bench, the diesel pump has no common faults and works well during work. At this time, distinguishing the idea and entering the deadlock in the negotiation, bewildered, and sensibly recalled in his mind for a while, but there are some key points that have not been checked.
6. In the end, it was still suspected that the common faults of the air intake were large. From the air filter element to the intake manifold, I checked it step by step. Finally, I found that there was a loan hole under the intake hose of the diesel engine, which caused the turbine gas to leak again.
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Common fault clearing
Remove the air inlet soft hose. Since the loan opening is too large to repair, it is recommended that the owner remove and replace the new air inlet rubber hose, install the rubber hose on the rack, tighten the fixed iron clamp, and debug. Common faults disappeared.
summary
Because the operating temperature of the part where the air inlet rubber hose is located is very high, embrittlement will occur for a long time, so the owner must check and deal with it in time to prevent larger common faults.
Of course, for such hidden common failure points, everyone must be careful and rational when repairing, and not be annoying, and finally they can find common failure points.
