Troubleshooting of oil break valve of NT855 diesel engine two cases       

1) a TY160 bulldozer suddenly turned off during a field operation and could not start again. The driver thinks that diesel is used up. But after filling the tank up with diesel fuel (before half a tank of diesel), it still failed to start. Because the starter can drive the engine, but the exhaust is smokeless, so it is decided that the oil circuit is faulty. Check the diesel filter has diesel oil, but start without diesel fuel to the injector (because the PT pump to break the oil valve between the diesel spill), so as to determine the failure of the oil valve. Check the oil cut-off valve line, that line to start switch off the oil valve off (as often on site operation caused by uneven), oil cut-off valve without current into the resulting oil cut-off valve valve is closed without the diesel engine. After the fastening joint restarts, the failure phenomenon disappears.

2) a TY220 bulldozer, after a winter operation, the engine can not flameout. It was found that when the throttle was increased, the engine speed increased, but accompanied by black smoke. When the oil circuit is checked, it is found that the filter element of the diesel filter is damaged and sundry. Remove the starting switch to the oil drain valve line, still can not flameout. According to the working principle of the oil cut-off valve, the valve when the oil valve is opened, there is diesel oil into the injector, then even if the switch off switch off. When the oil breaking valve is disassembled, it is found that the sealing surface of the valve plate is covered with sundries, so that the return spring can not be returned in time, so that the fire can not be extinguished. After cleaning the sealing surface of the valve plate, the valve body and the oil circuit, replacing the filter element of the diesel filter and filling with -35 light diesel oil, the fault phenomenon disappears.