A Jiefang J6 tractor, equipped with Xichai 6dl2 engine, is fixed on the Jinan Xinjiang line all year round. Recently, the vehicle is weak, and the valve clearance becomes smaller or even disappears. When I went to the service station for maintenance, I found that the valve sank and was seriously worn. Because the service station does not have the technical equipment to replace the valve seat ring. The owner had no choice but to replace the cylinder head assembly, resulting in considerable economic losses.
Through understanding, the vehicle operates the Shandong Xinjiang line all the year round. The configuration of the vehicle is unreasonable. The 350 HP 6dl2 engine is equipped with a 12 Speed overdrive transmission plus 4.11 main reduction ratio, and the 17.5m plate is pulled. The altitude of this line changes greatly, which is easy to cause insufficient power, overload of engine capacity, high temperature and increased wear of local valves.
The owner did not maintain and replace the air filter in time or bought a fake, resulting in dust entering the cylinder, hard carbon deposition on the top of the piston and abrasive wear of the valve. The owner also failed to check the valve clearance regularly. After checking it once at 100000 km, he never checked it again. When the fault occurs, the valve clearance has been very small or disappeared, the cylinder pressure drops, the valve timing deviates, and the vehicle’s weakness is inevitable.
If there are technical and conditional maintenance, the seat ring can be removed after boring the sheet, and the liquid nitrogen cooled seat ring can be inserted into the cylinder head, so as to ensure that the replaced seat ring is firm as new. However, the technical strength of most service stations is weak. They can’t replace the valve seat ring alone. They can only replace the cylinder head assembly, which also increases the economic pressure of car owners to a certain extent.
Just like this car, its route fluctuates greatly, and the engine is often overloaded due to unreasonable configuration; The owner checks the valve clearance according to the regulations, and the maintenance and replacement of the air filter are appropriate. There will be no such serious failure. Replacing a cylinder head is a material cost of thousands of yuan, not counting the auxiliary material man hour cost and the economic loss of stopping the vehicle.
In fact, according to the requirements of the manual, regular inspection and adjustment of various parameters is a process of maintenance instead of repair. Many truck drivers disagree. They still think that this car has not moved any parts for several years and tens of thousands of kilometers, which is a good car. In fact, this idea has misunderstandings.
Mechanical products are worn. Regular inspection is to find out the worn places, eliminate these adverse factors through adjustment or replacement, and make the vehicle run healthily all the time. If you don’t check and maintain at ordinary times and wait until something goes wrong, generally speaking, it won’t be a small problem and the economic loss is heavy; It seems that they don’t spend money at ordinary times. They spend more money after the failure. Correct understanding and implementation of the method of replacing repair with maintenance is the real way to save money.
I often hear some drivers say that my car hasn’t moved a screw for many years and thousands of kilometers, and the valve clearance hasn’t been adjusted. In fact, this is wrong. Only when the vehicle is inspected and maintained normally according to the regulations can it operate in a healthy condition and reduce the probability of breaking down on the road. Repair after a problem occurs is often not a small problem, and the corresponding cost is not small. The correct maintenance method of maintenance instead of repair is to prolong its service life, which is the way to save money.
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