DAF CF65, CF75, CF85 Series . Manual — part 466

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3-3

Inspection and adjustment

XE ENGINE FUEL SYSTEM

CF65/75/85 series

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8

3.2 INSPECTING INJECTOR OPENING PRESSURE

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Fuel or test fluid discharged by an

injector may penetrate the skin,

seriously harming your health. Make

sure the fuel jet is discharged into a

suitable container.

1.

Disconnect the earth lead from the battery

terminal.

2.

Remove the fuel injector pipes as a set and

close the connections on the pump units

immediately.

Note:

The opening pressure of the injectors can be

tested using an injector test pump

(DAF no. 0694966). The advantage of this

method is that the injectors need not be

removed from the engine.

3.

Check the opening pressure of the injectors.

Instructions for the use of the injector test
pump
1.

Before the injector test pump is used, it must

first be bled.

Remove the pump reservoir filler plug and fill

the reservoir with test fluid. The fluid level

must be approximately 1 cm below the top

rim.

2.

Tilt the pump until the line with the word

"BLEED" is horizontal.

M4059

BLEED

XE ENGINE FUEL SYSTEM

3-4

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200324

Inspection and adjustment

8

CF65/75/85 series

4

3.

Press the bleed pin (1) and simultaneously

turn the crank (2) clockwise to the stop.

During this procedure, air bubbles will come

to the surface in the reservoir. Now turn back

the crank, fill the reservoir again and repeat

the process until no more air bubbles come

to the surface.

Now release the bleed pin. Continue turning

the crank until fuel escapes on the delivery

side.

4.

If necessary, fill the fuel reservoir and screw

back the cap.

5.

The pump is now ready for use.

Inspecting opening pressure with an injector
test pump
1.

Keep the test pump more or less horizontal.

2.

Loosen the test pump filler cap by half a turn

so that air can enter the reservoir.

3.

Turn the test pump crank clockwise. The

compression will now start. Watch the fluid

level in the test pump.

4.

Carefully determine the opening pressure of

the injector. There is no harm in repeating

the test two or three times.

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If the test is repeated too often,

however, the test fluid deposited on

the piston may cause damage to the

engine when it is started.

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M4058

i 400190

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200324

3-5

Inspection and adjustment

XE ENGINE FUEL SYSTEM

CF65/75/85 series

4

8

3.3 INSPECTING INJECTOR OPERATION

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Fuel or test fluid discharged by an

injector may penetrate the skin,

seriously harming your health. Make

sure the fuel jet is discharged into a

suitable container.

Evaluating the injector's spray pattern, spray

angle, and sound is practically impossible. New

injectors or injectors that have been in use for

some time cannot be tested in this way.

1.

Place the injector on an injector tester.

2.

First allow the injector to inject a number of

times.

3.

Inspect the injector for:

-

opening pressure

-

leakage

-

injector nozzles.

Opening pressure
1.

Inspect the discharge pressure by slowly

building up the pressure inside the injector.

Leakage
1.

Dry the nozzle immediately after the final

injection.

2.

Increase the pressure to the opening

pressure minus 20 bar. Within approx. 10

seconds, fuel must have ceased to leak from

the nozzle. A moist nozzle is permitted. If the

injector does not pass the oil leakage test, it

must be replaced.

Injector nozzles
1.

Quickly build up pressure in the injector and

check whether all the nozzles are fully open.

2.

Clean the injector if possible. See

"Cleaning".

XE ENGINE FUEL SYSTEM

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200324

Inspection and adjustment

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CF65/75/85 series

4

3.4 INSPECTING FUEL SYSTEM FOR LEAKAGE

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To prevent deformation of the fuel

tank, the delivery pressure in the fuel

tank must not exceed 0.4 bar.

1.

Fit a pressure reducer valve connection on a

tank cap (without bleeder) and connect the

tank cap to the fuel tank.

2.

Dry the inspection points.

3.

Pressurise the fuel tank (maximum 0.2 bar).

4.

Unscrew the union nut (A) a few turns to

check whether there is leakage in the non-

return valve. If there is leakage, the banjo

bolt should be replaced.

5.

Check the whole fuel system (low-pressure

section) for leaks.

6.

De-pressurise the system and replace the

banjo bolt with integrated non-return valve

on the rear of the filter housing with a normal

banjo bolt.

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