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5 Brakes

5-1 Service brake, parking brake and breakaway brake

Reasons for rejection

Mandatory equipment

1. If fitted to a trailer:

a) a service brake does not act on each road wheel of at least one axle, or

b) a parking brake does not act on each wheel of at least one axle.

2. Where the vehicle inspector is able to identify the laden weight (Note 5) of the trailer and its load, the trailer is not fitted with a service brake, parking brake, or breakaway brake, as required by Table 5-1-1.

3. An agricultural trailer with a laden weight (Note 5) of more than 2000kg that does not comply with braking requirements is not fitted with two safety chains that cross each other when the trailer is connected (refer to section 8, Towing connections).

Condition
Service brake

4. There is corrosion damage (Note 1) within 150mm of a brake component mounting point.

5. A vacuum hose or pipe (including connections) is:

a) insecure, or

b) leaking, or

c) damaged (cracked, chafed, twisted, stretched or corroded, eg showing signs of pitting or a noticeable decrease in the pipe’s outside diameter)

6. The brake vacuum servo (brake booster) is:

a) not functioning fully or adequately, or

b) leaking, or

c) insecure.

7. The brake master cylinder is:

a) leaking brake fluid, or

b) insecure, or

c) excessively corroded, or

d) reservoir fluid level is below the minimum indicator where this is visible externally.

8. A brake valve is:

a) not operating (eg has a seized load sensing valve), or

b) leaking brake fluid, or

c) insecure, or

d) excessively corroded.

9. A brake pipe (including connections) is:

a) leaking brake fluid, or

b) insecure, or

c) deformed from its original shape, or

d) chafed, or

e) corrosion damaged, eg there are signs of pitting or a noticeable increase in the pipe’s outside diameter.

10. A flexible hydraulic brake hose (including connections):

a) is leaking brake fluid, or

b) is insecure, or

c) bulges under pressure, or

d) is twisted, stretched or chafed, or

e) external sheathing is cracked to the extent that the reinforcing cords are exposed, or

f) has metal connections that are excessively corroded, or

g) has an end fitting that is not attached to the hose by means of swaging, machine crimping or a similar process (Note 2).

11. The service brake cable:

a) is knotted, frayed or excessively corroded, or

b) has an auxiliary tensioner fitted, or

c) has otherwise deteriorated so that it may affect the parking brake performance.

12. A service brake actuating rod or guide:

a) is excessively corroded, or

b) is excessively worn, or

c) has otherwise deteriorated so that it may affect the parking brake performance.

13. A brake calliper:

a) shows visible signs of leaking, or

b) is insecure, or

c) is seized.

14. A brake backing plate is:

a) insecure, or

b) severely corroded, or

c) deformed from its original shape, or

d) cracked, or

e) contaminated by brake fluid, oil or grease.

15. A wheel cylinder:

a) shows visible signs of leaking, or

b) is insecure, or

c) is seized.

16. An ABS system component is damaged, insecure or missing.

17. A brake disc or drum is:

a) worn beyond manufacturer’s specifications (where visible without removing vehicle components)
(Note 3), or

b) fractured or otherwise damaged (where visible without removing vehicle components) (Note 3), or

c) contaminated by brake fluid, oil or grease.

18. A brake friction material (where visible without removing vehicle components) (Note 3) is:

a) worn below manufacturer’s specifications, or

b) is separating from the brake pad backing plate or brake shoe, or

c) is contaminated by brake fluid, oil or grease.

19. A service brake component shows signs of heating or welding after original manufacture.

Parking brake

20. The parking brake lever:

a) travels excessively, or

b) is insecure, or

c) mounting is damaged, corroded, distorted or fractured within 150mm of the lever mounting, or

d) mechanism or lever pivot bearing is worn or damaged so that the parking brake could be easily released by accident.

21. The parking brake cable:

a) is knotted, frayed or excessively corroded, or

b) has an auxiliary tensioner fitted, or

c) has otherwise deteriorated so that it may affect the parking brake performance.

22. A parking brake actuating rod or guide:

a) is excessively corroded, or

b) is excessively worn, or

c) has otherwise deteriorated so that it may affect the parking brake performance.

23. A parking brake component shows signs of heating or welding after original manufacture.

Performance
Service brake

24. The service brake is not able to be applied in a controlled and progressive manner.

25. When the service brake is applied and without assistance from the towing vehicle’s engine:

a) the combined effort of the trailer and towing vehicle brakes does not stop the vehicle combination within 7m from a speed of 30km/h (average brake efficiency of 50%), or

b) the vehicle vibrates under braking to the extent that control of the vehicle is adversely affected, or

c) (direct trailer brake) the brake fails to release immediately after the towing vehicle’s brakes are released, or

d) (indirect trailer brake) the brake fails to release when the towing vehicle stops decelerating, or the directional control is affected, eg swerving to one side, or the brakes on one side apply more slowly than on the other side, or

e) the brake balance, during the entire brake application, varies by more than 20% between wheels on a common axle.

26. The ABS or brake system warning lamp or self-check system, if fitted, indicates a defect in the ABS or brake system (this does not apply to brake pad wear warning systems).

Parking brake

27. When the park brake is applied:

a) the vehicle does not stop within 18m from a speed of 30km/h (average brake efficiency of 20%), or

b) it does not hold the vehicle at rest on a slope of 1 in 5, or

c) it does not hold all the wheels on a common axle stationary against attempts to drive the vehicle away.

Breakaway brake

28. The breakaway brake does not automatically and immediately apply when the trailer is disconnected from the towing vehicle (Note 4).

Note 1

Agricultural trailer means a trailer that is used exclusively for agricultural or land management purposes, and that is operated on the road only for the following purposes:

a) during delivery from a manufacturer to the manufacturer’s representative, or

b) while being delivered to or from an agricultural show for display or demonstration purposes, or

c) while being taken to or from a farm, or from one part of a farm to another part of that farm.

Axle means a transverse shaft or housing on which a vehicle’s wheels are mounted.

Brake friction material means a brake component having a friction surface that is designed to be preferentially sacrificed.

Breakaway brake means a service brake or parking brake fitted to a trailer that ensures, under all conditions of use, that, if the trailer is unintentionally disconnected from its towing vehicle, the brake will automatically and immediately apply and will remain applied for at least 15 minutes.

Corrosion damage is where the metal has been eaten away, which is evident by pitting. The outward signs of such corrosion damage is typically displayed by the lifting or bubbling of paint. In extreme cases, the area affected by the corrosion damage will fall out and leave a hole.

Direct trailer service brake means a service brake fitted to a trailer that allows the driver of a towing vehicle, by operating the service brake of the towing vehicle, to directly and progressively regulate the trailer brake effort.

Engine brake is a modification to a diesel engine used to increase the retardation force provided by the engine on deceleration.

Friction surface means any surface of a brake component that is designed to convert kinetic energy to heat.

Indirect trailer service brake means a service brake fitted to a trailer where the action of the driver of a towing vehicle applying the brakes of that vehicle results in a reaction by the trailer that is used to progressively regulate the trailer brake effort.

Laden weight means the weight of the vehicle and its load for the time being carried.

Modify means to change a vehicle from its original state by altering, substituting, adding or removing a structure, system, component or equipment, but does not include repair.

Parking brake means a brake readily applicable and capable of remaining applied for an indefinite period without further attention.

Repair means to restore a damaged or worn vehicle, its structure, systems, components or equipment to within safe tolerance of its condition when manufactured, including replacement with undamaged or new structures, systems, components or equipment.

Service brake means a brake for intermittent use that is normally used to slow down and stop a vehicle.

Note 2

Hose end fittings that can be undone using hand tools are unacceptable.

Note 3

If a brake is fitted with an inspection port plug, this must be removed for inspection of the brake components.

Note 4

A breakaway brake, if fitted, must be tested, but is not required to be functional on a trailer with a laden weight of 2500kg or less that is fitted with one or two compliant safety chains as required in Table 5-1-1. The vehicle inspector should advise the vehicle operator if the breakaway brake is not functional.

Note 5

Laden weight means the weight of the trailer and its load, if any, for the time being carried. A vehicle inspector may be presented with a trailer (usually unladen, such as a boat, car or horse trailer) that has a laden weight below 2000kg, but that is likely to have a laden weight exceeding 2000kg when it carries its normal load. In such a case, the vehicle inspector should make the vehicle operator aware, for example by putting a note on the checksheet, that the trailer may not comply with safety chain or brake requirements when the trailer carries its normal load.

Table 5-1-1. Trailer brake requirements

Type of brake required

Laden weight (Note 5) of the trailer

2000 kg or less

2001–2500 kg

2501 kg or more

Service brake

Not required but, if fitted, must act on each wheel of at least one axle

Required; either direct or indirect service brake must act on each wheel of at least one axle

Required; direct service brake must act on each wheel of at least one axle

Parking brake

Not required

Not required

Required; must act on at least one complete axle

Breakaway brake (Note 1) (Note 4)

Required unless fitted with an appropriate coupling and safety chain

Required, unless fitted with an appropriate coupling and two safety chains

Required

(Note: Safety chains are recommended - but not required)

Summary of legislation

Applicable legislation
Mandatory equipment

1. A trailer must be fitted with a service brake, parking brake, or breakaway brake depending on the laden weight (Note 5) of the trailer, as listed in Table 5-1-1.

2. An agricultural trailer with a laden weight (Note 5) of more than 2000kg that does not comply with brake requirements must be fitted with two safety chains that cross each other when the trailer is connected (refer to section 8, Towing connections).

Permitted equipment

3. A trailer may be fitted with a type of brake that is not required to be fitted to the trailer.

Condition

4. A brake must be in good condition.

5. The brake friction surfaces must be within safe tolerance of their state when manufactured, and must not be scored, weakened or damaged to the extent that the safety performance of the brake is adversely affected.

Performance

6. The service brake must be able to be applied in a controlled and progressive manner.

7. When a vehicle’s brake is applied:

a) the vehicle or its controls must not vibrate to the extent that control of the vehicle is adversely affected, and

b) the braking effort on each wheel must provide stable and efficient braking without adverse effect on the directional control of the vehicle, and

c) if the vehicle is equipped with an anti-lock braking system (ABS), the wheels must not lock, other than when the speed of the vehicle falls below the ABS activation parameters set by the vehicle manufacturer.

8. The trailer’s and towing vehicle’s service brakes must together stop the vehicle combination within a distance of 7m from a speed of 30km/h without damage to, or permanent deformation of, either the coupling system or the structure of either vehicle, and without assistance from the compression of the towing vehicle’s engine or other retarders.

9. A trailer parking brake must stop the trailer within a distance of 18m from a speed of 30km/h, or hold the trailer at rest on a slope of 1 in 5.

10. A breakaway brake must automatically and immediately apply when the trailer unintentionally disconnects from the towing vehicle, and must remain applied for at least 15 minutes.

Page amended 1 November 2014 (see amendment details).