Pay attention to eight things when repair diesel engines

Pay attention to eight things when repair diesel engines
1, “three leakage” 
Repair of diesel engine control and resolve when the “three leakage” problem, can take “five words” criteria, that is strict, cleaning, wiping, grinding, tight. Yan: the removal and installation of parts to strict requirements, abide by the rules, is strictly prohibited Cookin Luanqiao, such as screw bolts tightened several times according to the order and not chaos without order screw to prevent part deformation. Clean: pre-assembled components, must be clean to prevent mixed with impurities. If a valve with the valve seat ring at a very small debris mixed, not only oil, but also directly affect the engine’s work. Wipe: In the asbestos pad, pad of paper and various plug the leak at the oil-coated asbestos. Wipe the oil when asbestos in thin and uniform, not too thick, they should not have cast the entire surface pad, just painting the local oil spill. Grinding: grinding or milling the combination of face parts, and its role is to restore the surface finish and accuracy, the pipe joints or gasket after grinding, can remain sealed, not oil. Tight: tightness of seals to fit, not too tight or too loose, such as the engine of the contact surface and sealing nuts, etc., must maintain the appropriate tightness.
2, the cylinder pressure 
In order to ensure there is enough cylinder pressure, with the gap between the piston and cylinder liner, piston ring end gaps must meet the requirements side, valve and valve seat seal, front seal better fuel injector, cylinder pad is better, and the thickness meet the requirements.
3, the combustion chamber volume 
Diesel engine has been repaired, often make the combustion chamber volume change and change the compression ratio, directly affect the normal operation of diesel engine, combustion chamber volume change factors: anti-loaded piston position, cylinder pad thickness properly, crank and connecting rod mechanical wear or bending, dislocation of the swirl chamber inserts, valves such as excessive settlement, repairs, deal with these situations attention.
4, timing 
When oil is being closed, including when and valve timing, if oil is not correct when, S195, X195-type diesel fuel injection pump and gear room can be covered with a gasket between the adjustment, increase or decrease each 0.1mm thick gasket equivalent to flywheel arc 6.3mm. If the valve is low, you should first check with the correct timing gear installed on the error, and then adjust the valve clearance, valve clearance changes every 0.1mm, 3 degrees crank angle changes, the equivalent flywheel arc length 11.1mm, adjustments should pay attention to the piston compressed to TDC, the intake and exhaust valve clearance (cold state) can not be less than 0.2mm, to prevent mechanical thermal expansion valve closed lax, or valve hit the piston head.
5, the “three filters” 
Poor technical condition of air filter, dust will enter the valve. Accelerate the piston rings, cylinder, valve and valve seat wear and tear early, causing difficulty in starting, power down. Diesel oil, oil filter technology, the state is not good, will gain access to the parts between the impurities, resulting in early wear three precision coupling, accelerate the crankshaft and bearing wear, will cause serious engine early retirement.
6, diesel spray 
Vice plunger, delivery valve and injector needle deputy vice state of technology is not good, will result in poor atomization fuel injection, the diesel engine start difficult, incomplete combustion, carbon deposition increased, resulting in decreased engine power, fuel Therefore, the fuel system, especially the precision coupling to carry out a check.
7, the through-hole and the hole closed
(1) through-hole is now closed to S195 diesel engine, for example, bearings, bushings 5 hole when installed on the positive.
a, main bearings, main bearings of each pair are drilling a hole on the tank, respectively, and the cylinder body, the spindle neck of the oil is also connected, installed, as long as the main bearings of the flange gap aligned pins, main bearings can prevent rotation, to ensure hole alignment, so that lubricating oil smooth and avoid burnout.
b, rocker arm bushings. Pressure to the arm into the sleeve, such as the holes are not aligned, rocker shaft and the bushing will be due to lack of lubrication, friction and burning of the dry valve clearance becomes large, serious percussion.
c, connecting rod bushing. Set of connecting rod small end hole drilled, and the connecting rod bushing hole connected to the connecting rod head set within the set of copper, if the two hole is not aligned, the occurrence of copper sleeve and piston pin “Dangdang” knock banging sound, and even killed.
d, start shaft bushing, shaft bushing installation starts, the two bushing hole to cover, respectively, with the body and the corresponding set of gear oil groove connected, otherwise the start shaft and bushing will accelerate wear and tear, caused by oil angle and with gas phase change, resulting in decreased engine power.
(2) holes are closed the following four holes
a, fuel tank cap vent. Plug the hole after the tank is no longer connected with the atmosphere, the tank top will be decreased due to negative pressure oil, causing oil supply disruption; fuel heated evaporation, so that increased pressure within the tank may cause leakage at the fuel tank switch, therefore, This hole is not blocked.
b, change the crankcase vent, for pore blockage, the crankcase exhaust piled up, the crankcase pressure rise, make the oil leakage, humidity exhaust gas mixed with oil, but also accelerate oil deterioration, accelerated wear and tear parts Therefore, maintenance must be clear in this hole.
c, fuel pump vent hole. Fuel pump vent hole on the plug, will lead to putting a small amount of diesel oil leakage between the catheter and into the fuel pump, dilute the lubricant inside the shell, accelerated component wear, therefore, this hole can not be blocked.
d, pump discharge hole, the hole if the blockage, leakage could not pump the water discharge into the bearing, the bearing will accelerate the damage, so be sure to clear the maintenance of this hole.
8, run 
(1) cold run. Remove the fuel injector, diesel engine running with the external drive, also check the engine oil pressure and temperature of each part, and pay attention to listen to the voice parts, after a cold run, while the temperature is high, release the oil, clean oil filter and oil passages.
(2) hot run. No-load heat run, note the work and all parts of diesel engine noise; heat load and time required to run, always pay attention to all parts of the mouth of channeling the sound and oil gas, smoke, fuel injector back to the oil and found that the problem should be immediately removed.