Land Transport Rule

Heavy-vehicle Brakes 2006

Rule 32015

This is Schedule 2 of the Heavy-vehicle Brakes Rule.


Schedule 2     Heavy Vehicle Braking Specification of 6 December 1998

0.0     Introduction

A.     This document is the operative version of the specification. It has been developed from previous drafts dated 7 June and 11 August, and incorporates amendments as at the above date. This version will be used as part of the assessment of vehicles to be operated at the new size and weight limits. Amendments may be made in the light of operating experience, and comments should be submitted to the Chairman of the Braking Committee, Mr R A Lambert, PO Box 12843, Auckland, or to the Controller, Vehicle Standards, Land Transport Division, Ministry of Transport, Wellington.

B.     Background


1.     Scope and limitations

A.     This specification applies only to vehicles which will be used in any combination at a GCM exceeding 39 tonnes.

B.     In this specification ‘operator’ may mean the owner, the operator, or the driver, as appropriate.

C.     Approval of vehicles to this code will be specific, ie will not be a ‘type approval’. Vehicle combinations must be semi-dedicated and will be specified on the approval. The test is to be applied to every specific vehicle and vehicle combination except as indicated below. For example a fleet of three trucks and three trailers may be proposed for use in any combination, but each combination must be specified, and the approval for each truck will list each trailer.

D.     Where identical trailers or semi-trailers are proposed for use with more than one truck or tractor, the testing of every combination will not be necessary provided that:


2.     Equipment requirements

A.     Service brakes must operate on every axle.

B.     In case of braking failure in any of the vehicles in a combination, each vehicle in the combination must either apply its brakes automatically, or leave the brakes under the control of the driver.

C.     Every vehicle (including trailers and semi-trailers) must have an emergency braking system which is substantially independent of the service braking system, and which operates on at least half of the axles on each vehicle, and which is operable from one control within easy reach of the driver in his normal seating position. This emergency braking would generally operate by the force of the springs in spring brake chambers, but the inclusion of ordinary air chamber operation is not prohibited; e.g. a three-axle trailer with air on the front axle and spring brakes on the rear bogie.

D.     Every vehicle (including trailers and semi-trailers) must have a parking brake system substantially independent of the service brakes, and which:

E.    All air connections between towing and towed vehicle shall be of the two-line type (excluding auxiliaries).

F.     Air-line identification

G.     Couplings

H.     Every vehicle submitted for testing to this specification must have travelled at least 500 km beforehand, with the vehicle braking equipment as fitted to the vehicle at the time of testing. The intention of this clause is to allow the brake system to ‘bed in’, especially the friction linings. If there is reasonable cause to suspect that this requirement has not been complied with, the vehicle shall be rejected.


3.     Pre-conditions for test

A.     Each vehicle must have a current certificate of fitness, and must be up to certificate of fitness standard.

B.     Towing connections must comply with NZS 5446 (full trailers) or NZS 5450/5451 (semi-trailers) as appropriate.

C.     Load anchorage points must comply with NZS 5444.

D.     Note that under (B) and (C) above, compliance with drafts current at the time will be deemed acceptable.

E.     Loads must be attached in accordance with the Truck Loading Code.

F.     Operator must complete data sheet for each submitted vehicle.

G.     Operator must mark the outer sidewall of each tyre with four equispaced radial white lines approx 100 mm wide, using acrylic paint or similar medium.

H.     Each axle must be weighed before the test within a time specified by the Auto Surveyor.

I.     Axle loadings must not exceed those to be permitted under new size and weight limits.


4.     Test requirements

A.     Each combination of vehicles must satisfactorily perform three successive controlled emergency stops from 50 km/hr when fully laden, using the service brakes only.

B.     Each combination of vehicles must also satisfactorily perform one controlled stop from 50 km/hr when fully laden, using the emergency brakes only.

C.     The tests shall be carried out on a flat straight sealed road (or equivalent surface) marked with lanes 3.7m wide, and the vehicle shall be in the centre of the lane each time braking commences.

D.     ‘Fully laden’ means laden to the maximum permitted under the new size and weight limits, with the payload distributed as evenly as possible along (or in) the load carrying portion of the vehicles. The axle loads shall be verified immediately before or after the test. In this context ‘immediately’ need not be taken literally, provided that there is no opportunity for off-loading between weighing and test.

E.     ‘50 km/hr’ means between 49 and 51 km/hr according to the towing vehicles speedometer unless there is reason to doubt the accuracy of that instrument, in which case calibration shall be arranged to the satisfaction of the Automotive Surveyor or Traffic Officer.

F.     ‘Controlled’ means:

G.    ‘Satisfactorily’ means that:

H.     ‘Using the service brakes only’ means that the transmission must be in neutral or the clutch disengaged so that there is no retarding effect from either the engine itself or from any exhaust brake or other type of retarder.


5.     The vehicle or vehicles must be presented by the operator at a time and place specified by the Automotive Surveyor. The test will be conducted with the operator driving, one Automotive Surveyor in the cab, and one or more Automotive Surveyors observing.

A.     Alternative arrangements may be made by the Automotive Surveyor in charge of the testing, provided that the spirit and intent of the specification is met.


6.     Ideally the test site will be flat straight road of say 0.5 km, with minimum street furniture, and with ample flat or approximately flat run-off areas. The test must be conducted when there is little or no other traffic and there must be suitable turning areas, or roads forming a circuit. The test area must be near a weighbridge, or portable weighing equipment must be available.


7.     Automotive Surveyors and Traffic Officers will cooperate to ensure that the tests may be carried out as smoothly as possible, and with no danger or inconvenience to other road users. If necessary, the road will be closed to other traffic for the duration of the tests.


8.     The test described in this specification is in addition to the normal certificate of fitness inspection. A fee will be charged based on the time taken, at the standard charge-out rate for Automotive Surveyors and Traffic Officers.


9.     Subsequent certificate of fitness inspections will verify that the details shown on the data sheet are still correct.


10.     Operators are to be recommended to carry out sufficient checking and/or testing beforehand, so that time is not wasted during the official tests. Operators are to be reminded that any such testing must not endanger or inconvenience other road users, and that such testing should be carried out at lower speeds initially. Any such advice must include the warning that the current weight limits still apply.


11.     Future requirements

A.     It is likely that this code will be applied only to existing vehicles. In the event that a ‘new’ vehicle is tested, the following additional requirements will apply (these will either be part of the final brake code or subject to new Regulations).


Vehicle Standards Bulletin – Excerpt November 29, 1988

A.     44 tonne assessment and brake test - Errata

1.     Instructions to Automotive Surveyors

2.     Instructions to Operators

3.     Heavy Vehicle Braking Specification

4.     Data Sheet - MOT 4076A

5.     Loading Certificate – MOT 4011A


R L Reynolds
Controller, Vehicle Standards


Assessment for New Size and Weight Limits December 6, 1988

Instructions to Operators

A.    If you have a vehicle or combination of vehicles that you wish to operate at the new size and weight limits


B.     The package for the new size and weight limits has the following features:

1. No changes will take place until EVERY part of the package is complied with:

2. All new vehicles will be required to comply with the new dimension limits and the pre-conditions listed above. For practical purposes this will be interpreted as:

3. All existing vehicles which are intended to take advantage of the new weight limits must also comply with the new dimensions. Existing vehicles that do not comply, may continue to be operated at the old limits.

4. All existing vehicles will be expected to comply with drawbar/drawbeam standard by 1 January 1989.

5. All existing vehicles will be expected to comply with fifth wheel/kingpin, and load anchorage point standards within a reasonable time (proposed 1 June 1990).

6. All vehicle combinations to be operated in excess of 39 tonnes must be assessed and tested for compliance.


C.     Combinations to exceed 39 tonnes.

1. Obtain from SANZ, as appropriate:

2. Obtain from a MoT Vehicle Testing Station:

3. Check that each vehicle complies with the items listed in (B1e), and that the braking performance complies with the specification.

4. Fill in the Data Sheet as far as you are able, and present it with any outstanding certificates and assessment fee ($200) to the Testing Station.

5. Arrange an appointment with the testing station manager for the assessment. Note that this may have to be in a regional centre rather than locally.

6. Turn up for the appointment:

7. The assessment fee is for cost-recovery, therefore a broken appointment will mean that the fee is forfeit.


R L Reynolds
Senior Automotive Engineer



A Division of the Ministry of Transport

29 May 1989


The format and complexity of the equipment requirements in the HMV Regulations has meant that the most convenient way to treat braking is to amend the Braking Specification.

Delete Sub-Clause lA and substitute the following:

1. Scope and Limitations



R L Reynolds
Controller Vehicle Standards


TELEPHONE (04) 828-300 FAX (04) 855-699, 855-799

Land Transport Rule - Heavy-vehicle Brakes - Rule 32015
Land Transport Safety Authority of New Zealand, Te Mana Marutau Waka Whenua o Aotearoa