Nanni QLS 47T - Fuel System Maintenance; Fuel Circuit Bleeding and Filter Replacement

B
A
C
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Fuel system
I Warning! : Total cleanliness must be guaranteed
when working on the fuel circuit. No impurities must en-
ter the injection pump and the injectors. Carry out each
of these operations with the engine cold and stopped.
Bleeding the fuel circuit
The fuel circuit is self-priming but manual bleeding is re-
quired after replacing the lter, after have running out of
fuel or after a work on the circuit if it has been emptied.
• Loose the drain valve screw A on the engine fuel
lter support.
• Pump the priming pump by pressing the button B
repeatedly until bubble-free fuel comes out of the
drain valve screw.
• Tighten the drain valve screw and lock the hand
pump.
I Caution! : Avoid draining all the fuel in the lter when
venting. If so, remove the lter and replenish with fuel
before replacing it and repeat the venting operations.
Maintenance
Replacing the fuel filter
This lter treats the water and impurities in the fuel be-
fore it enters the injection circuit.
• Cut the fuel intake at the tank.
• Place a receptacle under the lter and then remove
the used lter C cartridge.
• Apply a thin layer of fuel over the seal surface of
the new lter cartridge before tting it.
• Tighten it by hand until the lter makes contact with
the lter head then tighten it by a half-turn.
• Untighten the drain valve screw to release the air.
Open the fuel valve again and drain the circuit.
• Start the engine and check the assembly is leak-
tight.
I Caution! : Used lters must be disposed of in an ap-
propriate container.
Replacing the fuel prefilter
The fuel prelter is an optional component that puries
the fuel before it is injected in the engine. These instruc-
tions are given as an example only.
• Close the fuel shutoff valve on the fuel tank.
• Place a receptacle under the fuel prelter. Remove
the lter tank
• Drain and clean the lter tank.
• Replace the cartridge and re-install the tank.
• Open the fuel valve. Drain the feed system then
start the engine to check the leak-tightness.
Draining the water from the fuel prefilter
Before starting the engine each time, ensure there is
no water in the fuel prelter. If there is water, place a
tray under the fuel prelter and then drain the water and
impurities using the bottom cap/valve.