DAF CF65 Series Service Manual page 251

4
CF65/75/85 series
The injector leak-off pipe is connected to the
return pipe to the fuel tank (1) via a non-return
valve in the fuel fine filter.
If the system has been 'open', the fuel system can
be bled by means of the integrated primer pump
in the fuel lift pump (3).
Pump unit
Operating principle
6
1
Situation A
In this situation the pump plunger (2) makes the
suction stroke.
Due to the constant overpressure in the supply
area of the fuel system, the high-pressure area
above the pump plunger (2) is filled via the fuel
supply ducts (3).
Situation B
In this situation the pump plunger (2) makes the
compression stroke.
As the valve (5) has not yet closed the link to the
fuel supply ducts (3), there is no pressure build-
up.
©
200324
A
5
4
3
2
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XE ENGINE FUEL SYSTEM
B
General
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