DAF CF65, CF75, CF85 Series . Manual - part 483

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 200324

2-7

General

XE ENGINE, ENGINE BRAKE

CF65/75/85 series

4

10

DEB operation, hydraulic
DEB disengaged

1.

Solenoid valve

2.

Control valve

3.

Operating piston

4.

Main piston

5.

Spring plate

6.

Bridge piece

7.

Exhaust valve

8.

Exhaust valve rocker

9.

Valve clearance set screw

10. DEB set screw

Note:

Rockers A and B are not one and the same rocker 

(see "Hydraulic control of exhaust valves").

A. Exhaust valve rockers

B. Exhaust valve rockers

The solenoid valve (1) is not activated. 

Lubricating oil cannot pass to the hydraulic part of 

the DEB.

In addition, a spring plate (5) ensures that the 

main piston (4) remains in the top position.

i 400159

7

6

3

2

10

1

9

4

5

8

A

B

XE ENGINE, ENGINE BRAKE

2-8

©

 200324

General

10

CF65/75/85 series

4

DEB engaged

The solenoid valve (1) is activated. Lubricating oil 

can pass to the hydraulic part of the DEB.

The pressure of the lubricating oil, at least 1.5 

bar, moves the control valve (2) upwards against 

the spring pressure and lifts the ball from its seat. 

The high-pressure area of the DEB is now filled 

with lubricating oil.

The oil causes the main piston (4) to move down, 

until it rests on the set screw (9) of the rocker (8).

i 400174

7

6

3

2

10

1

9

4

5

8

A

B

©

 200324

2-9

General

XE ENGINE, ENGINE BRAKE

CF65/75/85 series

4

10

During the next upward movement of the rocker 

(8), the main piston (4) will be moved upwards. 

The main piston (4) begins to build up pressure, 

causing the ball in the control valve (2) to close off 

the oil supply.

i 400175

7

6

3

2

10

1

9

4

5

8

A

B

XE ENGINE, ENGINE BRAKE

2-10

©

 200324

General

10

CF65/75/85 series

4

If the main piston (4) continues to move up, this 

movement is transferred hydraulically to the 

operating piston (3).

The operating piston (3) moves downwards 

against the spring pressure, opening one exhaust 

valve.

In the case of loss of oil during operation, this will 

automatically be compensated for by the control 

valve (2).

i 400176

7

6

3

2

10

1

9

4

5

8

A

B