Maintenance manual for sunray hfc4da1-2c china-IV diesel engines
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engine.
z After the fuel is used up.
z After the water drainage from the fuel-water separator.
z After the replacement of fuel filter
Replacement of fuel filter
1. Replacement interval of fuel filter: Once every 7,000km;
2. Water separation interval: Once every 5,000Km;
3. It’s prohibited to use any used fuel filter.
IV. Low pressure fuel delivery pump
The low pressure fuel delivery pump is one gear pump and is stalled
at the rear end within the high pressure pump housing. The low
pressure fuel delivery pump continually supplies the required fuel
amount to the high pressure pump from the fuel tank.
The fuel delivery pump is functioned to supply sufficient fuel
supply to the high pressure pump under following conditions:
(1) Under any working condition;
(2) Under necessary pressure;
(3) Throughout the entire service life.
The low pressure fuel delivery pump is one mechanical gear pump and is installed at the rear end of high pressure
pump and driven by the high pressure pump shaft. Its main parts are two gears rotating in opposite direction. While
rotating, two gears engages to vacuumize the fuel into the chamber formed between gears and pump walls and then
conveys to the outlet (pressure end). The closing line of the rotating gears realizes the sealing between vacuumization
end and pressure end of the pump and prevents the fuel backflow.
The fuel supply amount of the gear pump is approximately in proportion to the engine speed. This is why the fuel
supply amount of the gear pump can be reduced by means of the throttle valve at the inlet end or can be restrained by
means of the relief valve at the outlet end.
No maintenance is required for the gear pump. Charge the fuel from the fuel system before the first start. When the
fuel in the fuel tank is used up, operate the manual fuel delivery pump to charge fully the low pressure fuel line.
V. Fuel pipeline
Besides the steel pipe, the low pressure fuel line can also adopt flame-retardant braided and armored fuel hose. The
fuel pipes shall be arranged in such manner to prevent the mechanical damage and that the fuel dripped or evaporated
will not concentrate nor burn.
In event of vehicle distortion, engine displacement, or similar conditions, the functions of the fuel pipeline shall not be
impaired. All fuel delivery pipelines shall have the radiation shield measures.
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