Brake Lining Wear pattern analysis
1 Poor bedding-in

recommends
Main Reasons:

Drum diameter is larger than lining radius. Drum wear.
Possible consequences:
If the wear pattern differs across the axle, vehicle pull can result; also excessive brake noise. Low efficiency.

recommends
Main Reasons:
Lining radius is larger than actual drum diameter. Bedding-in period for the lining was too short.
Possible consequences:
Vehicle pull and exessive brake noise may occur. Low efficiency.
recommends
Main Reasons:
Beding-in period for the lining was too short. Drum wear.
Possible consequences:
Rapid lining wear. Vehicle pull and exessive brake noise may occur. Low efficiency.
4 Circumferential grooves

recommends
Main Reasons:

Poor drum condition.
Possible consequences:
Vehicle pull and excessive brake noise may occur. Low efficiency.

6 Deep irregular circumferential grooves

recommends
Main Reasons:

Large particles loose in the brake. Very poor drum condition.
Possible consequences:
Very high lining and drum wear. Squeal.

2 Steps in the lining surface

recommends
Main Reasons:

There may be a step in the brake drum surface. General drum wear.
Possible consequences:
Rapid lining wear. Vehicle pull and exessive brake noise may occur. Low efficiency.

8 Lining surface tapered

recommends
Main Reasons:

Brake shoes misaligned with the brake drum.
Possible consequences:
The linings may lock onto the drum when braking from high speeds. Vehicle pull and excessive brake noise may occur. Low efficiency.

9 Glazed lining surface

recommends
Main Reasons:

Low brake actuation. The linings are not working hard enough, probably dur to the incorrect adjustment of the braking mechanism, wrong size brake chambers or sticking brake shoes.
Possible consequences:
Rapid lining wear on another axle. Low efficiency. Squeal.

12 Dirt on the lining surface

recommends
Main Reasons:

Dirt particles in the brake.
Possible consequences:
High lining and drum wear. Low efficiency. Vehicle pull and excessive brake noise may occur.

13 Build up a dirt between lining & brake shoe

recommends
Main Reasons:

Shoe radius out of line. Shoe platform not parallel. Lining rivited incorrectly (wrong rivets, riveted with too low force).
Possible consequences:
Cracks in the lining material. Loose linings. Squeal.

2 Steps in the lining surface

recommends
Main Reasons:

There may be a step in the brake drum surface. General drum wear.
Possible consequences:
Rapid lining wear. Vehicle pull and exessive brake noise may occur. Low efficiency.

3 Scarred lining surface

recommends
Main Reasons:

Poor drum condition. Eg, heat crazing.
Possible consequences:
Rapid lining wear. If linings not 100% bedded-in. Low efficiency can result.

5 Grooved lining surface

recommends
Main Reasons:

Small loose particles in the brake.
Possible consequences:
Very high lining and drum wear. Squeal.

7 Uneven lining surface

recommends
Main Reasons:

Wrongly adjusted or worn axle bearings.
Possible consequences:
Very high lining and drum wear. Squeal.

10 Greasy lining surface

recommends
Main Reasons:

Broken or improperly mounted hub oil seals. Excessive lubrication of the bearings or the braking mechanism.
Possible consequences:
Vehicle pull and excessive brake noise may occur. Low efficiency.

11 Spray painted brake linings

recommends
Main Reasons:

Careless spray painting.
Possible consequences:
Vehicle pull and excessive brake noise may occur. Low efficiency.

14 Cracks around rivet holes

recommends
Main Reasons:

Too heavy riviting force. Wrong shape of rivet heads. Brake shoes radius does not conform to lining radius. Brake shoe platform is not clean or even.
Possible consequences:
Lining and drum breakage. Brake over heating. Noise.

15 Large fractures in lining surface

recommends
Main Reasons:

Faults in brake mechanism. Sticking brake shoes (weak return springs). Excessive use of brakes at high speed. Overloaded vehicle. Too large air chambers.
Possible consequences:
High lining wear. Vehicle pull and excessive brake noise. Low efficiency.

16 Burnt lining surface

recommends
Main Reasons:

Faults in brake mechanism. Sticking brake shoes (weak return springs).
Possible consequences:
High lining wear. Vehicle pull and excessive brake noise. Low efficiency.

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Padstow NSW 2211     
Ph: (02) 9774 3011    
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