Check and judge the technical status of the parts
1, piston pair technical status check and judgment
(1) observation: To observe the most serious wear parts of the nail marks, lateral paddling has obviously feeling, should be replaced with new parts.
(2) experience: piston clean diesel, and the sleeve is filled with diesel, use your fingers to push the plunger sleeve into the oil and oil return hole and the center holes are blocked strict, then take the length of the 1/3 after the plunger to relax, if can return immediately, that can continue to use; otherwise you should get a new piece.
(3) pressure gauge inspection method: on the pump head connected with the pressure gauge, the throttle on the supply position, open decompression and shake the car, the plunger pump oil to speed 30 times per minute, while the pressure must be greater than 19 thousand and 600 kPa; otherwise, you should get a new piece.
2 、 check and judge the technical status of the oil outlet valve
(1) observation method: observe the sealing ring belt, if it is sunken and the width is more than 0.5 millimeters, or there is obvious abrasion groove mark on the reducing pressure band, when the original bright surface is not seen, new parts should be replaced.
(2) oil pressure test method: remove the high pressure oil cylinder by check, open the Baotou Benz fuel pump accessories inspection window, the plunger shake down to the stop point, hand pump oil pump, first remove the oil in the air, after the observation of high pressure oil pipe joints have no leakage phenomenon. If there is leakage, new parts should be replaced (this cannot check the pressure band).
(3) pressure gauge inspection: this check should be done with checking the plunger pressure. When the fuel pressure indicator is stabilized at the end of the pressure drop, the time required for the pressure indicator to be equal to 19 thousand and 600 kPa drops to 17 thousand and 650 PA, if not less than 15 seconds, it is well sealed. Immediately after the pressure is increased to 24 thousand and 520 kPa, the oil is broken. Note the hand swing back position, if the 0.98-6.87 kPa shows normal decompression. Only when the tightness is good can you see the exact value of the pendulum.
When the above inspection is still in trouble, the oil outlet valve shall be removed and worn after cleaning. If there is no obvious groove mark, the high pressure copper pad has no wear and tear. After cleaning, the tight cover can be tightened and the tight seat can be returned to normal. Otherwise, it should be replaced with new parts.
3, northern Baotou Benz Parts Injector technical status check and judgment
This check shall be carried out under the condition that both the piston pair and the oil outlet valve work properly.
(1) test on the car: when other parts of the engine are normal, the nozzle can be adjusted first and then loaded into the car. When the engine starts, then through the “listen to the sound, look at the exhaust” approach in the car debugging.
(2) standard nozzle comparison method: this method is used in advance to adjust the normal fuel injection nozzle and checked nozzle comparison. The three pipes are connected in parallel with the fuel injection pump, then the air in the oil circuit is discharged and the throttle is placed at the maximum position. Turn on the pressure swing car and observe whether the injection conditions of the two injectors are identical. If the two of them inject oil simultaneously or stop the injection at the same time, the atomization state is consistent, indicating that the nozzle being inspected is qualified.
(3) Baotou North Benz fittings pressure gauge inspection method: with three tubes, the pressure gauge and the checked fuel injector are connected in parallel with the injection pump, put the throttle in the maximum position. Turn on the pressure reducing pump, and press the pressure to 9 thousand and 800 PA (combined with adjusting spring). Then, about 10 times a minute to make the fuel injection nozzle, at this time may not drip phenomenon. When the above work is completed, re adjust the needle valve to the required pressure and then perform atomization test at about 80 times per minute. Droplets should be fine and evenly distributed, the direction of oil beam, cone angle should meet the requirements, the oil cut should be crisp, and there is a special ringing sound.
After the above inspection, when there is still a fault, the needle valve, the top rod and the spring should be removed for cleaning and checking. If it is seriously damaged and cannot be restored to normal, new parts should be replaced.

Two, to extend the service life of parts
In addition to the quality of products, the root cause of the damage is mainly due to improper use of the machine and timely and incorrect maintenance. Here are a few points to extend the service life of the pair of measures taken for reference.
1, strict implementation of fuel deposition filtration system, the filling of diesel fuel should be at least 48 hours after precipitation to use. The diesel oil shall be in accordance with the seasonal standard model. Refueling tools to clean special. Refueling and storage of oil should also be clean, so as to avoid dirt mixed with fuel and accelerate the wear of parts, reduce the service life of parts.
2, strict technical maintenance specifications, fuel filter 100 hours of work, tank cleaning work 500 hours each time, if it is found that the filter breaking loss effect timely replacement, shall not be removed while the use of DC supply. The fittings should be removed and checked for 500 hours under normal working conditions. Make sure that the place, hand, tools and cleaning oil are clean in case of contamination. The demolition operation shall not luanqiao cookin, cleaning not cluttered, should not and other non couples together wash, to avoid bumps, bruises. During assembly, the assembly position shall not be changed at will to meet the requirements of the machine. When putting on the tight seat of the oil valve and the tight cap of the choke, it should be tightened according to the specified torque to ensure the good technical condition of the injector and the injection pump after assembly.
3, in addition to the above requirements, should also improve the understanding of the dual structure, characteristics and working principle of understand parts, strengthen and improve the dual parts maintenance, operation and use, do not adjust without fault, maintenance without demolition, maintenance is not luanqiao cookin, cleaning and maintenance don’t wipe touch, the assembly and adjustment of chaos when the modified twist, all according to the standard technical requirements, in order to achieve the purpose of prolonging the service life.