DAF LF45, LF55 Series. Manual - part 267

©

 200508

2-3

General

CLUTCH

ΛΦ45/55 series

3

9

2.3 OVERVIEW DRAWING, CLUTCH LEVER ATTACHMENT TO CLUTCH 

HOUSING

V300397

1

2

3

4

6

7

5

1.

Screw adapter

2.

Ball joint

3.

Clutch lever

4.

Thrust bearing

5.

Clip

6.

Claw

7.

Yoke pin

CLUTCH

2-4

©

 200508

General

9

ΛΦ45/55 series

3

©

 200508

3-1

Description of components

CLUTCH

ΛΦ45/55 series

3

9

3. DESCRIPTION OF COMPONENTS

3.1 CLUTCH SERVO

Declutching
Depressing the clutch pedal results in a build-up 

of hydraulic pressure.

This causes the servo piston (1) to push the air 

valve (2) away from the valve seat, against the 

force of the springs (3) and (7).

3

2

7

1

10

8

9

 A-A

4

5

6

A

V300352-2

A

CLUTCH

3-2

©

 200508

Description of components

9

ΛΦ45/55 series

3

Air pressure now flows into the cylinder.

The pressure pin (4) is pushed forward by the air 

pressure building up on air piston (5) and the 

hydraulic pressure on fluid piston (6).

The pressure pin (4) pushes against the clutch 

lever, which results in declutching.

State of equilibrium
When the hydraulic pressure and pneumatic 

support push the pressure pin (4) forwards, a 

state of equilibrium is achieved between the air 

pressure and the hydraulic pressure (status when 

the clutch pedal is not depressed any further).

The servo piston (1) again seals off against the 

valve seat, closing the air supply and stopping the 

build-up of pneumatic pressure.

Clutching
When the clutch pedal is released, there is no 

longer any hydraulic pressure and the servo 

piston (1) will be pushed back into its original 

position by pressure spring (7) and any remaining 

pneumatic support.

As a result, the bleed bore (8) in the servo piston 

(1) is no longer closed, and venting takes place 

via bleed vent (9).

Vent opening
The function of the vent opening (10) is to prevent 

a build up of pressure between both piston seals.