Summarize the correct replacement method and process of QSB7 electronic control engine and QSL9.3 electronic control engine for non-road engineering machinery, hope to help the operators and maintenance friends.
No matter which engine you need to follow two principles in the replacement process:
First observe whether the first oil-water separator contains too much impurities. If it is too much, it is necessary to clean the diesel tank in time or clean the diesel tank regularly.
In order to prevent impurities from entering the fuel system during the replacement process, the filter is strictly prohibited from being pre-filled. The filter should be installed in an empty state on the diesel filter holder. Then, the manual oil pump is used to pump the filter and remove the low-pressure oil.
CUMMINS QSB7’s three diesel filter replacement process
The QSB7 is equipped with three diesel filters, the first and second oil water separators and the third diesel fine filter.
Fuel system air discharge process
Low pressure fuel system: Turn counterclockwise to unlock the manual fuel pump handle. Press the pump handle until you feel resistance and can no longer press the handle (ie, the air filter needs to be pressed about 140 times) to lock the pump handle.
High-pressure fuel system: Before starting the engine, there is no need to release air from the high-pressure fuel system. The motor should be used to drive the engine to remove air from the high-pressure fuel system.
The whole vehicle is unloaded and the engine is started. If the engine cannot start after 30 seconds, return the key switch and press the oil pump again. Repeat the above steps until the engine starts normally.
The engine may be unstable for a few minutes after starting the engine and the noise level may increase. This is normal because air is being expelled from the system.
Three-way diesel filter replacement process for QSL9.3
QSL9.3 is equipped with three diesel filters, which are the first and second oil-water separators and the third diesel fine filter.
Fuel system air discharge process
Low-pressure fuel system (including diesel tank, low-pressure vane pump, three-way filter, diesel pipeline, etc.), loosen the fuel pump pressure relief valve on the diesel pump, manually press the pump handle to make the diesel filter and high-pressure oil pump full of fuel. Tighten the fuel pump pressure relief valve on the diesel pump and press the pump handle until you feel resistance and can no longer press the handle.
High-pressure fuel system (including high-pressure oil pump, high-pressure common rail, fuel injector, high-pressure fuel pipe, etc.), before starting the engine, there is no need to release air from the high-pressure fuel system. The motor should be used to drive the engine to remove air from the high-pressure fuel system. .
The whole vehicle is unloaded and the engine is started. If the engine cannot start after 30 seconds, return the key switch and press the oil pump again. Repeat the above steps until the engine starts normally.
After replacing the fuel filter, the two engines may cause fault code 559 (low fuel rail pressure) due to air entering the system. In this case, be sure to run the engine until the air is exhausted.
