DAF CF65, CF75, CF85 Series . Manual - part 1158

©

 200423

3-15

Inspection and adjustment

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

ΧΦ75 series

5

3.21 INSPECTING THE COMPRESSOR LINE

Remain at a safe distance from 

rotating and/or moving components.

Note:

If excessive values are measured, the inside of 

the air-dryer housing and the silencer on the vent 

should first be cleaned. Then repeat the 

inspection.

1.

Bring the engine up to operating 

temperature. 

2.

Bleed the system to a pressure below the 

cut-in pressure of the pressure regulator.

3.

Remove compressor control line (1) which is 

hooked up to connection point 23 of the air 

dryer. Then seal the opening at connection 

point 23.

4.

Build up pressure in the brake system 

(pressure regulator must cut out).

5.

When the engine is not running, remove the 

safety valve from the compressor line and 

replace it with a test nipple.

6.

Connect a pressure gauge (measuring range 

0-16 bar) to the test nipple.

7.

Start the engine and run it at maximum 

speed.

}

R600521

1

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

3-16

©

 200423

Inspection and adjustment

5

ΧΦ75 series

8.

The pressure gauge should indicate a 

pressure below 2 bar with the pressure 

regulator switched off.  If the measured 

pressure exceeds the value indicated, the 

compressor line should be cleaned or 

replaced.

Note:

If the pressure measured is too high, there is 

excessive carbon deposit in the compressor 

line. This may be due to the poor condition of 

the compressor (oil consumption).

9.

Run the engine at idling speed.

10. Bleed the brake system until the cut-in 

pressure of the pressure regulator has been 

reached and switch off the engine. The 

needle of the pressure gauge may not drop 

too quickly now. If necessary, check the 

system for air leakage. Pay particular 

attention to the compressor line and 

compressor.

11. Fit the safety valve.

12. Connect the compressor control line to 

connection point 23 of the air dryer.

R600249

©

 200423

3-17

Inspection and adjustment

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

ΧΦ75 series

5

3.22 CHECKING THE BRAKE COMPONENTS AND BRAKE SYSTEM FOR LEAKS

1.

While operating the service brake, check 

whether any leaks occur in the brake system.

If the brake system of a vehicle has been 

charged to the maximum pressure, it should 

generally be possible to drive the vehicle 

after a period of 16 hours of uninterrupted 

standstill, without having to first charge the 

brake system to adequate operating 

pressure. This implies a maximum pressure 

drop of approx. 0.4 bar per hour at normal 

system pressure. 

Note:

Always connect auxiliary consumers and 

accessories to circuit 4.

EXPLANATORY NOTES ON THE MAINTENANCE ACTIVITIES

3-18

©

 200423

Inspection and adjustment

5

ΧΦ75 series

3.23 INSPECTING THE AUTOMATIC BRAKE ADJUSTER

Brake drum

Inspection, brake adjuster travel
1.

Measure the basic setting L1.

2.

Measure the position when the brakes are 

applied, L2 (minimum brake system 

pressure 6 bar).

3.

Calculate the brake stroke L3 = L2 - L1, see 

"Technical data". If the brake stroke differs 

from the specified value, take the following 

action: 

4.

Check whether the control plate (1) is locked 

in respect of the fixed bracket.

5.

If not, turn the control plate as far as possible 

(until the internal stop is felt) in the direction 

in which the brake adjuster is moved during 

braking.

6.

Fix the control plate in this position using the 

attachment nut on the fixed bracket.

7.

Check the internal slip using a torque 

wrench. 

Inspection, internal slip
1.

Make certain that there is sufficient pressure 

in the reservoirs (6.5 bar minimum).

2.

Release the parking brake.

3.

Fit a torque wrench on the hexagonal 

adjusting bolt and turn this counter-

clockwise. For the permitted value, see 

"Technical data".

If the specified reverse torque is not 

reached, but the worm shaft already turns at 

a lower value, the brake adjuster should be 

replaced.

M6101

L2

L1

M6005

1