DAF CF65, CF75, CF85 Series . Manual — part 445

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3-5

Inspection and adjustment

PE ENGINE FUEL SYSTEM

CF65/75/85 series

4

5

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".

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Inspection and adjustment

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CF65/75/85 series

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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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Inspection and adjustment

PE ENGINE FUEL SYSTEM

CF65/75/85 series

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7.

Remove the valve covers.

8.

Re-pressurise the system (maximum

0.2 bar).

9.

Check the permeable seal and the side-

connection of the injectors for leaks.

Note:

Engine oil may be used to detect leaks at the

O-ring.

10. Fit the valve covers.

11. Replace the normal banjo bolt with a banjo

bolt with integrated non-return valve.

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Inspection and adjustment

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CF65/75/85 series

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3.5 BLEEDING THE FUEL SYSTEM

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While bleeding the fuel system, fuel

will escape. Collect the fuel to avoid

the risk of fire.

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Dirt in the fuel system can lead to

significant damage to pump units

and housing.

Note:

The fuel system has to be bled if it has been

opened; this can be done in two ways.

-

With the fuel lift pump

-

By pressurising the fuel tank

Bleeding using the fuel lift pump
1.

Loosen the union nut on the injector.

2.

Pump fuel out of the injector pipe with the

primer pump until no more air bubbles are

visible in the fuel.

3.

Tighten the union nut to the specified torque,

see "Technical data".

4.

Repeat points 1, 2 and 3 for the other

injectors.

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