DAF LF45, LF55 Series. Manual - part 453

©

 200436

2-33

Description of components

OPERATION OF BRAKE COMPONENTS

ΛΦ45/55 series

6

3

2.18 DISC BRAKE CONSTRUCTION, WABCO MODEL

PAN 17 and PAN 19-1+ versions

Operation
Brakes

This disc brake operates using a pneumatic 

brake cylinder or spring brake cylinder.

If the brake is applied, the brake cylinder push 

rod presses against the eccentrically mounted 

lever (1).

Via brake cylinder 2 and pressure plate 3, the 

brake pad is pressed against the inside of the 

brake disc (4).

Due to the reaction force at the eccentric, the 

floating brake calliper (5) will also press the 

opposite brake pad with the same force.

Adjusting
If the eccentrically mounted lever (6) is operated 

by the push rod of the brake cylinder, the pin (7) 

on the lever will rotate the adjuster (8) and the 

pressure cylinder (9) in the outgoing stroke until 

the play has been eliminated.

If the brake is no longer being operated, the 

lever (6) will turn the adjuster (8) back in the 

opposite direction. The spring (10) in the adjuster 

will ensure that the pressure cylinder will hardly 

rotate. The result is that a small total play of about 

0.5 mm will remain between the brake pads and 

brake disc.

Brake pad wear wires
Brake pad wear wires are fitted to the brake pads. 

These wires are cut through when the brake 

lining has been worn down to the minimum 

thickness.

This is the signal for the VIC system to activate 

the "brake pad wear" warning symbol on DIP-4.

R600573

R600574

1

3

5

4

2

R600579

9

7

8

6

10

OPERATION OF BRAKE COMPONENTS

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©

 200436

Description of components

3

ΛΦ45/55 series

6

PAN 19-2 version

Operation
Brakes

This disc brake operates using a pneumatic 

brake cylinder or spring brake cylinder.

If the brake is applied, the brake cylinder push 

rod presses against the eccentrically mounted 

lever (1).

The brake pad is forced against the inside of the 

brake disc via the brake piston (2) and the 

pressure plate (3).

Due to the reaction force at the eccentric, the 

floating brake calliper (4) will also press the 

opposite brake pad with the same force.

Adjusting
This adjuster and the eccentric are equipped with 

teeth (6) that engage each other.

If the play is too great, the adjuster (7) will be 

rotated by these teeth the next time the brakes 

are applied, so that the play will be reduced.

Under normal conditions, the adjuster will push 

against the brake pad before rotation can take 

place. However, if rotation does take place, it will 

be absorbed by a slip coupling.

By removing one of the rubber caps (8) where the 

automatic adjuster is located, a hexagon is 

revealed. Using a ring spanner, the play can be 

manually set by adjusting this hexagon.

Brake pad wear wires
Brake pad wear wires are fitted to the brake pads. 

These wires are cut through when the brake 

lining has been worn down to the minimum 

thickness.

This is the signal for the VIC system to activate 

the "brake pad wear" warning symbol on the 

instrument panel.

R600578

3

4

1

2

R600577

6

7

8

5

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 200436

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Description of components

OPERATION OF BRAKE COMPONENTS

ΛΦ45/55 series

6

3

2.19 DISC BRAKE CONSTRUCTION, KNORR MODEL

The disc brake construction consists of the brake 

disc and the brake calliper. There are two 

variants of this construction:

-

Knorr SB7000, recognisable by the divided 

housing between the brake cylinder and the 

brake pad holder.

-

Knorr SN7000, recognisable by the 

undivided housing between the brake 

cylinder and the brake pad holder.

The operation of the two variants is identical. 

Only the reconditioning of the brake calliper is 

different.

The Knorr SB7000 construction has been used 

since the introduction of the LF 45/55 series. The 

Knorr SN7000 construction is used in production 

from week 41-2002 on all front axles and on air-

sprung rear axles (Class 3 vehicles). On leaf-

sprung rear axles the Knorr SB7000 construction 

is still used. The operation of the two variants is 

identical. Only overhauling and the parts of the 

brake calliper differ.

Operation
Brakes

This disc brake operates using a pneumatic 

brake cylinder or spring brake cylinder.

If the brake is applied, the brake cylinder push 

rod presses against the eccentrically mounted 

lever (1).

Via the bridge (2) and the threaded bushes (3), 

the brake pad is pressed against the brake 

disc (4) at two points on the inside.

Due to the reaction force at the eccentric, the 

floating brake calliper (5) will also press the 

opposite brake pad with the same force.

R600707

SB7000

SN7000

OPERATION OF BRAKE COMPONENTS

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©

 200436

Description of components

3

ΛΦ45/55 series

6

Adjusting
One of the two threaded bushes (3) is equipped 

with the mechanics for automatic adjustment of 

the play between the brake pads and brake disc.

This adjuster and the eccentric are equipped with 

teeth (6) that engage each other.

If the play is too great, the adjuster (8) will be 

rotated by these teeth the next time the brakes 

are applied, so that the play will be reduced.

Under normal conditions, the adjuster will push 

against the brake pad before rotation can take 

place. However, if rotation does take place, it will 

be absorbed by a slip coupling.

The rotation of the adjuster is transferred by 

means of a chain (7) to the other adjuster.

By removing a rubber cap (9) where the 

automatic adjuster is located, a hexagon is 

revealed. Using a ring spanner, the play can be 

manually set by adjusting this hexagon.

4

5

1

3

2

R600486

R600487

3

7

6

8

3

9