DAF LF45, LF55 Series. Manual - part 648

©

 200515

3-21

Inspection and adjustment

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

ΛΦ45/55 series

5

3.26 INSPECTION AND ADJUSTMENT, LOAD SENSING VALVE, LEAF 

SUSPENSION

Explanatory notes on instruction plate

The data relating to axle loads and output 

pressures are listed on the instruction plate 

following the sequence of the axles beneath the 

vehicle.

"1" refers to the (first) front axle, "2" to the 

following axle, etc.

In the entire column, a reading of 6 bar has been 

filled in under "1". If the vehicle is equipped with 

an empty/load valve, a pressure ratio is entered 

in the box under the valve illustration, e.g. "i = 1 : 

1,5". The "output pressure P2" of axle 1 will give 

variable readings.

These values can be used to check the brake 

pressure values of the front axle and to carry out 

the inspection/adjustment below at the same 

time. To do this, connect a pressure gauge to the 

test connection of one of the front axle brake 

cylinders.

Inspection/adjustment
1.

Measure the weight plus load of the rear 

axle.

2.

Check the attachment of the control lever 

and its ease of operation.

3.

Check that the right type of valve has been 

fitted.

4.

Check the length of the control lever 

(see "L" on the instruction plate).

5.

Connect a pressure gauge (4) to the test 

connection near connection 1/4 on the load 

sensing valve (input pressure).

6.

Connect pressure gauge (2) to the test 

connection on one of the brake cylinders 

(service brake connection) of the rear axle.

7.

Make sure that the reservoir pressure is 

higher than 6.5 bar throughout the testing 

process.

8.

Depress the brake pedal until pressure 

gauge (4) indicates a value of 6 bar.

9.

Read the brake pressure of the rear axle 

from pressure gauge 2 and check that this 

value matches the one listed on the 

instruction plate in the table under "output 

pressure p2" to the rear axle.

R6 00 549

1/4

4

2

2

R600562

1

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

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©

 200515

Inspection and adjustment

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ΛΦ45/55 series

10. If necessary, correct the brake pressure by 

adjusting the length of the vertical 

connecting rod (2). Never attempt to alter the 

length L of the (horizontal) control lever.

11. Remove the ball coupling (1) and raise the 

control lever. Check that the output pressure 

is now allowed through (almost) without 

reduction.

Note:

The small socket head screw in the centre of 

the valve must not be adjusted.

Drive and chassis

1

2

R6 00 568

L

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 200515

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Inspection and adjustment

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

ΛΦ45/55 series

5

3.27 CHECKING THE DIFFERENTIAL FOR LEAKS

1.

Visually inspect the differential for leaks. 

3.28 CHECKING THE OPERATION OF THE DIFFERENTIAL LOCK

1.

Jack up the rear axle and support the axle on 

stands.

2.

Bring the air system to operating pressure.

3.

Engage the differential lock. The warning 

indicator should now be active.

4.

Check that there is a "rigid" connection 

between the driven wheels.

5.

Disengage the differential lock. The warning 

light should now go out and the "rigid" 

connection between the driven wheels 

should be broken.

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

3-24

©

 200515

Inspection and adjustment

5

ΛΦ45/55 series

3.29 CHECK THE DRIVE SHAFT PLAY

1.

Check the universal joints (2) and 

suspension bearing (3) for play and damage.

2.

Check the sliding joint for axial and radial 

play. The rubber dust cover (1) over the 

sliding joint should be undamaged.

3.

There must be no clearly perceptible play on 

the universal joints, suspension bearing and 

the sliding joint.

3.30 INSPECTING THE FIFTH WHEEL

1.

Check the attachment of the fifth wheel.

2.

Check the play of the closing gear of the fifth 

wheel.

Note:

For maximum play values, consult the 

manufacturer's instructions or the legal 

requirements.

3.

In the case of fifth wheels with a plastic 

sliding plate (1), check for wear. The plastic 

sliding plate (1) must not lie flush with the top 

of the attachment bolts.

1

2

3

V3 00 379

V300372

1

2