DAF LF45, LF55 Series. Manual - part 279

©

 200416

2-1

BE Engine fuel system

TECHNICAL DATA

ΛΦ45/55 series

4

0

2. BE ENGINE FUEL SYSTEM

2.1 GENERAL

Fuel level element

Fuel fine filter

Lift pump

High-pressure pump

Fuel rail

Fuel rail pressure-limiting valve

Injector

Injector washer

Angular displacement

70



Maximum pressure drop across fuel fine filter

2.0 bar

Fuel lift pump pressure in front of fine filter (with 

engine at idling speed)

5 - 13 bar

Fuel lift pump pressure behind fine filter (with en-

gine at idling speed)

3 - 11 bar

Pressure relief valve opening pressure

11 bar

Maximum underpressure on suction side of fuel 

lift pump

0.5 bar

Pump pressure (dependent on the operating 

mode of the engine and the electronic calibration)

300 - 1400 bar

Fuel rail pressure (dependent on the operating 

mode of the engine and the electronic calibration)

300 - 1400 bar

Opening pressure

1650 bar

Number of holes in injector

8

Resistance of magnet coil

0,15 - 0,5 



i400693

A

Nozzle length (dis-

tance A)

Washer thickness

21.5 

≥ 0.2 mm

1.5 mm

23.0 

≥ 0.2 mm

3.0 mm

TECHNICAL DATA

2-2

©

 200416

BE Engine fuel system

0

ΛΦ45/55 series

4

Fuel return overflow valve

Fuel return pipe

Return fuel measurement

Fuel return overflow valve opening pressure

1.2 - 2.0 bar

Maximum return pipe pressure build-up

0.2 bar

Maximum quantity of return fuel at idling speed

120 ml/min.

Minimum permitted time for filling a measuring 

beaker to a volume of 360 ml

3 min.

©

 200416

2-3

BE Engine fuel system

TECHNICAL DATA

ΛΦ45/55 series

4

0

2.2 TIGHTENING TORQUES

The tightening torques specified in this section 

are different from the standard tightening torques 

cited in the overview of the standard tightening 

torques. The other threaded connections not 

specified must therefore be tightened to the 

torque cited in the overview of standard 

tightening torques.

When attachment bolts and nuts are replaced, it 

is important that - unless stated otherwise - these 

bolts and nuts are of exactly the same length and 

property class as those removed.

Electronic unit cooling plate

Low-pressure fuel pipes

High-pressure pump

High-pressure fuel pipe

Fuel rail

Injector pipes

Fuel supply pipe

Injectors

Attachment bolts holding the electronic unit to the 

cooling plate

10 Nm

Attachment bolts holding the cooling plate to the 

engine block

24 Nm

VOSS quick-release coupling fittings

18 Nm

Banjo bolts

24 Nm

VOSS quick-release coupling fittings

24 Nm

Fuel return overflow valve in cylinder head

24 Nm

Attachment nuts holding the high-pressure pump 

to the timing gear case

25 Nm

High-pressure pipe union nut

22 Nm

Attachment bolts

24 Nm

Pressure-limiting valve

100 Nm

Injector pipe union nuts

22 Nm

Fuel supply pipe nut

50 Nm

Injector clamping bracket attachment bolts

10 Nm

Injector electrical connection

1.5 Nm

TECHNICAL DATA

2-4

©

 200416

BE Engine fuel system

0

ΛΦ45/55 series

4