2.2.

Characteristics of braking systems 2.2.1. Vehicles of categories M and N 2.2.1.1. The set of braking systems with which a vehicle is equipped shall satisfy the requirements laid down for the service, secondary and parking braking systems. 2.2.1.2. The equipment providing service, secondary and parking braking may have common components, provided that they fulfil the following conditions: 2.2.1.2.1. There shall be at least two controls, independent of each other and readily accessible to the driver from his normal driving position. For all categories of vehicles, except m2 and M3, every brake control (excluding a retarder control) shall be designed such that it returns to the fully-off position when released. This requirement shall not apply to a parking brake control (or that part of a combined control) when it is mechanically locked in an applied position. 2.2.1.2.2. The control of the service braking system shall be independent of the control of the parking braking system. 2.2.1.2.3. Where the service and secondary braking systems have the same control, the effectiveness of the linkage between that control and the various components of the transmission systems shall not be liable to diminish after a certain period of use. 2.2.1.2.4. Where the service and secondary braking systems have the same control, the parking braking system shall be so designed that it can be actuated when the vehicle is in motion. This provision shall not apply where an auxiliary control permits at least partial actuation of the service braking system, as provided for in Annex II, point 2.1.3.6. 2.2.1.2.5. In the event of a breakage of any component other than the brakes (as defined in point 1.6) or the components specified in point 2.2.1.2.7, or of any other failure of the service braking system (malfunction, partial or total exhaustion of an energy reserve), the secondary braking system or that part of the service braking system which is not affected by the failure shall be able to bring the vehicle to a halt in the conditions prescribed for secondary braking. 2.2.1.2.6. In particular, where the secondary braking system and the service braking system have a common control and common transmission: 2.2.1.2.6.1. Where the service braking system is actuated by the muscular energy of the driver assisted by one or more energy reserves, the secondary braking performance shall, in the event of failure of that assistance, be capable of being ensured by the muscular energy of the driver assisted by the energy reserves, if any, which are unaffected by the failure, the force applied to the control not exceeding the prescribed maxima. 2.2.1.2.6.2. Where the forces for the service braking system and transmission depend exclusively on the use of an energy reserve controlled by the driver, there shall be at least two completely independent energy reserves, each provided with its own independent transmission; each of them may act on the brakes of only two or more wheels so selected as to be capable of ensuring by themselves the prescribed degree of secondary braking performance without endangering the stability of the vehicle during braking; in addition, each of these energy reserves shall be fitted with a warning device as defined in point 2.2.1.13. 2.2.1.2.7. Certain parts, such as the pedal and its bearing, the master cylinder and its piston(s) (hydraulic systems), the control valve (hydraulic and/or pneumatic systems), the linkage between the pedal and the master cylinder or the control valve, the brake cylinders and their pistons (hydraulic and/or pneumatic systems), and the lever-and-cam assemblies of brakes, shall not be regarded as liable to breakage if they are amply dimensioned, are readily accessible for maintenance, and exhibit safety features at least equal to those prescribed for other essential components (such as the steering linkage) of the vehicle. Where the failure of any such part would make it impossible to brake the vehicle with a performance at least equal to that prescribed for the secondary braking system that part shall be made of metal or of a material with equivalent characteristics and shall not be subject to significant distortion in the normal operation of the braking equipment. 2.2.1.3. Where there are separate controls for the service and secondary braking systems, simultaneous actuation of the two controls shall not render both the service and secondary braking systems inoperative, either when both braking systems are in good working order or when one of them is faulty. 2.2.1.4. In the event of failure in a part of the transmission of the service braking system, the following conditions shall be met: 2.2.1.4.1. A sufficient number of wheels shall still brake by actuation of the service braking system control, whatever the vehicle load. 2.2.1.4.2. These wheels shall be so selected that the residual performance of the service braking system satisfies the requirements laid down in point 2.1.4 of Annex II. 2.2.1.4.3. However, the above requirements shall not apply to towing vehicles for semi-trailers when the transmission of the service braking system of the semi-trailer is independent of that of the towing vehicle. 2.2.1.5. Where use is made of energy other than the muscular energy of the driver, there need not be more than one source of such other energy (hydraulic pump, air compressor, etc.), but the means by which the device constituting that source is driven shall be as safe as practicable. 2.2.1.5.1. In the event of failure in any part of the transmission of a vehicle's braking systems, the supply to the part not affected by the failure shall continue to be ensured where this is required for the purpose of halting the vehicle with the degree of effectiveness prescribed for residual and/or for secondary braking. This condition shall be satisfied by means of devices which can be easily actuated when the vehicle is stationary, or by automatic means. 2.2.1.5.2. Furthermore, storage devices located down-circuit of this device are such that in the event of a failure in the energy supply, after four full-stroke actuations of the service braking system control under the conditions prescribed in point 1.2 of Annex IV, sections A and B, it is still possible to halt the vehicle at the fifth application with the degree of effectiveness prescribed for secondary braking. 2.2.1.5.3. However, for hydraulic braking systems with stored energy, these provisions can be considered to have been satisfied, provided that the requirements of point 1.2.2 of Annex IV, section C, are satisfied. 2.2.1.6. The requirements of points 2.2.1.2, 2.2.1.4 and 2.2.1.5 shall be satisfied without the use of any automatic device of a kind such that its ineffectiveness might pass unnoticed because the parts which are normally in an ‘at rest’ position are actuated only in the event of failure of the braking system. 2.2.1.7. The service braking system shall act on all the wheels on the vehicle. 2.2.1.8. The action of the service braking system shall be appropriately distributed among the axles. In the case of vehicles with more than two axles, in order to avoid wheel-locking or glazing of the brake linings, the brake force on certain axles may be reduced to zero automatically when carrying a much reduced load, provided that the vehicle meets all the performance requirements prescribed in Annex II. 2.2.1.9. The action of the service braking system shall be distributed between the wheels of the same axle symmetrically in relation to the longitudinal median plane of the vehicle. 2.2.1.10. The service braking system and the parking braking system shall act on braking surfaces permanently connected to the wheels through components of adequate strength. It shall not be possible to disconnect a braking surface from the wheels; however, in the case of the service braking system and secondary braking system, such disconnection of the braking surfaces shall be permitted provided that it is only momentary, for instance during a change of gear, and that both the service braking system and the secondary braking system continue to operate with the prescribed degree of effectiveness. In addition, any such disconnection shall be permitted in the case of the parking braking system, provided that it is controlled exclusively by the driver from his driving seat by a system which cannot be actuated by a leak ( 6 ). 2.2.1.11. Wear of the brakes shall be easily compensated by means of a system of manual or automatic adjustment. In addition, the control and the components of the transmission and of the brakes shall possess a reserve of travel and, if necessary, suitable means of compensation such that, when the brakes become heated or when the brake linings have reached a certain degree of wear, effective braking shall be ensured without immediate adjustment being necessary. 2.2.1.11.1. Wear adjustment shall be automatic for the service brakes. However, the fitting of automatic adjustment devices shall be optional for off-road vehicles of categories N2 and N3, and for rear brakes of vehicles of categories M1 and N1. Automatic wear adjustment devices shall be such that after heating followed by cooling of the brakes, effective braking is still ensured. In particular, the vehicle shall remain capable of normal running after the tests conducted in accordance with Annex II, point 1.3 (Type I test) and Annex II, point 1.4 (Type II test), or point 1.6 (Type III test). 2.2.11.2. It shall be possible to easily check this ear on service brake linings from the outside or underside of the vehicle, utilising only the tools or equipment normally supplied with the vehicle; for instance, by the provision of appropriate inspection holes or by some other means. Alternatively, acoustical or optical devices warning the driver at his driving position when lining replacement is necessary are acceptable. The removal of front and/or rear wheels shall be permitted for this purpose on category M1 and N1 vehicles only. 2.2.1.12. In hydraulic braking systems: 2.2.1.12.1. The filling ports of the fluid reservoirs shall be readily accessible; in addition, the containers of reserve fluid shall be so made that the level of the reserve fluid can be easily checked without the containers having to be opened. Where this last condition is not fulfilled, a warning light shall indicate to the driver when the reserve fluid falls to a level liable to cause a failure of the braking system. The driver shall be able to check easily whether the light is functioning properly. 2.2.1.12.2. The failure of a part of a hydraulic transmission system shall be signalled to the driver by a device comprising a red tell-tale lamp lighting up not later than on actuation of the control and remaining lit as long as the failure persists and the ignition (start) switch is in the ‘on’ (run) position. However a device comprising a red tell-tale lamp lighting up when the level of the fluid in its reservoirs falls below the value specified by the manufacturer shall be admissible. The tell-tale lamp shall be visible even by daylight; the satisfactory condition of the lamp shall be easily verifiable by the driver from the driver's seat. The failure of a component of the device shall not entail total loss of effectiveness of the braking system in question. 2.2.1.12.3. The type of fluid to be used in the hydraulic transmission of braking systems should be identified in accordance with ISO standard 9128-1987. The relevant symbol according to Figure 1 or 2 shall be affixed in a visible position in indelible form within 100 mm of the filling ports of the fluid reservoirs, additional information may be provided by the manufacturers. 2.2.1.13. Any vehicle fitted with a service braking system actuated by an energy reservoir shall, where the prescribed secondary braking performance cannot be obtained by means of this braking system without the use of stored energy, be provided with a warning device — in addition to a pressure gauge where fitted — giving an optical or acoustic signal when the stored energy in any part of the system falls to a value at which, without recharging of the reservoir and irrespective of the loading conditions of the vehicle, it shall be possible to apply the service braking system control a fifth time after four full-stroke actuations and obtain the prescribed secondary braking performance (without faults in the service-brake transmission and with the brakes adjusted as closely as possible). The warning device shall be directly and permanently connected to the circuit. When the engine is running under normal operating conditions and there are no faults in the braking system, the warning device shall give no signal except during the time required for charging the energy reservoir(s) after start-up of the engine. 2.2.1.13.1. However, in the case of vehicles which are only considered to comply with the requirements of point 2.2.1.5.1 by virtue of meeting the requirements of point 1.2.2 of Annex IV, section C, the alarm device shall consist of an acoustic signal in addition to an optical signal. These devices need not operate simultaneously, provided that each of them meets the above requirements and the acoustic signal is not actuated before the optical signal. 2.2.1.13.2. This acoustic device may be rendered inoperative while the parking brake is applied and/or, at the choice of the manufacturer, in the case of automatic transmission the selector in the ‘park’ position. 2.2.1.14. Without prejudice to the requirements of point 2.1.2.3, where the use of an auxiliary energy source is essential for the operation of a braking system, the energy reserve shall be such as to ensure that, should the engine stop, or in the event of a failure of the means by which the energy source is driven, the braking performance remains sufficient to bring the vehicle to a halt in the prescribed conditions. In addition, if the muscular energy applied by the driver to the parking braking system is reinforced by some aid, the actuation of the parking braking system shall be ensured in the event of failure of that aid, if necessary by using a reserve of energy independent of that normally supplying such aid. This reserve of energy may be that intended for the service braking system. The expression ‘actuation’ also covers the action of releasing. 2.2.1.15. In the case of a motor vehicle to which the coupling of a trailer equipped with a brake controlled by the driver of the towing vehicle is authorised, the service braking system of the towing vehicle shall be fitted with a device so designed that if the trailer braking system should fail, or the air supply line (or such other type of connection as may be adopted) between the towing vehicle and trailer should break, it will still be possible to brake the towing vehicle with the effectiveness prescribed for the secondary braking system; it is accordingly prescribed, in particular, that this device be fitted to the towing vehicle ( 7 ). 2.2.1.16. The auxiliary equipment shall be supplied with energy in such a way that during its operation the prescribed performance values can be reached and that even in the event of damage to the source of energy, the operation of the auxiliary equipment cannot cause the reserves of energy feeding the braking systems to fall below the level indicated in point 2.2.1.13. 2.2.1.17. Where a trailer belongs to category O3 or O4, the service braking system must be of a continuous or semi-continuous type. 2.2.1.18. In the case of a vehicle authorised to tow a category O3 or O4 trailer, the braking system shall satisfy the following conditions: 2.2.1.18.1. When the secondary braking system of the towing vehicle is actuated, there shall also be a graduated braking action on the trailer. 2.2.1.18.2. Should the service braking system of the towing vehicle fail, and if this system is made up of at least two independent sections, the section or sections not affected by this failure must be able partially or fully to actuate the trailer brakes. It shall be possible to graduate this braking action; if this operation is achieved by a valve which is normally at rest, then such a valve may only be incorporated if its correct functioning can easily be checked by the driver, either from within the cab or from outside the vehicle, without the use of tools. 2.2.1.18.3. In the case of a fracture or leak in one of the air supply lines (or in such other type of connection as may be adopted), it shall nevertheless be possible for the driver to fully or partially actuate the trailer brakes, by means either of the service braking system control or of the secondary braking system control or of the parking braking system control, unless the fracture or leak automatically causes the trailer to be braked with the performance prescribed in point 2.2.3 of Annex II. 2.2.1.18.4. In the case of a two-line air supply system, the requirement in point 2.2.1.18.3 shall be considered to be met if the following conditions are fulfilled: 2.2.1.18.4.1. When the designated brake control of the controls mentioned in point 2.2.1.18.3 is fully actuated, the pressure in the supply line shall fall to 1,5 bar within the following two seconds. 2.2.1.18.4.2. When the supply line is evacuated at the rate of at least 1 bar/s, the automatic braking of the trailer shall start to operate before the pressure in the supply line falls to 2 bar. 2.2.1.19. The following vehicle types shall satisfy the Type IIA test described in point 1.5 of Annex II and not the Type II test described in point 1.4 of that Annex: — inter-urban motor-coaches and long-distance touring motor-coaches of category M3 — and motor vehicles of category N3 authorised to tow trailers of category O4. Where the maximum mass of this vehicle exceeds 26 000 kilograms, the test mass shall be limited to 26 000 kilograms, or in the case where the unladen vehicle mass exceeds the mass of 26 000 kilograms, this mass is to be taken into account by calculation. 2.2.1.20. In the case of a motor vehicle equipped to tow a trailer with electric braking systems, the following requirements shall be met: 2.2.1.20.1. The power supply (generator and battery) of the motor vehicle shall have a sufficient capacity to provide the current for an electrical braking system. With the engine running at the idling speed recommended by the manufacturer and all electrical devices supplied by the manufacturer as standard equipment of the vehicle switched on, the voltage in the electrical lines, at maximum current consumption of the electrical braking system (15 A), shall not fall below the value of 9,6 V measured at the connection. The electrical lines must not be capable of short-circuiting even when overloaded. 2.2.1.20.2. In the event of a failure in the towing vehicle's service braking system, where that system consists of at least two independent units, the unit or units not affected by the failure shall be capable of partially or fully actuating the brakes of the trailer. 2.2.1.20.3. The use of the stop-light switch and circuit for actuating the electrical braking system is permissible only if the actuating line is connected in parallel with the stop-light and the existing stop-light switch and circuit are capable of taking the extra load. 2.2.1.21. In the case of a pneumatic service braking system comprising two or more independent sections, any leakage between those sections at or downstream of the control shall be continuously vented to atmosphere. 2.2.1.22. Motor vehicles of categories M2, M3, N2 and N3 with not more than four axles shall be equipped with anti-lock systems of category 1 in accordance with the requirements of Annex X. 2.2.1.23. If motor vehicles not mentioned in point 2.2.1.22 are fitted with anti-lock systems, they shall comply with the requirements of Annex X. 2.2.1.24. In the case of a motor vehicle authorised to tow a trailer of category O3 or O4 the service braking system of the trailer may only be operated in conjunction with the service, secondary or parking braking system of the towing vehicle. 2.2.1.25. Motor vehicles authorised to tow a trailer equipped with an anti-lock system, with the exception of vehicles of categories M1 and N1, shall be fitted with a separate optical warning signal for the anti-lock system of the trailer, meeting the requirements of points 4.1, 4.2 and 4.3 of Annex X. They shall also be equipped with a special electric connector for the anti-lock systems of trailers, in accordance with Annex X, point 4.4 of this Directive. 2.2.1.26. Motor vehicles of category M1 may be equipped with temporary-use spare wheels/tyres, provided they meet the requirements of Annex XIII. 2.2.2. Vehicles of category O 2.2.2.1. Trailers of category O1 need not be fitted with a service braking system; however, if trailers of this category are equipped with a service braking system, this shall comply with the same requirements as those of category O2. 2.2.2.2. Every trailer of category O2 shall be fitted with a service braking system either of the continuous or semi-continuous type or of the inertia (overrun) type. The latter type shall be authorised only for trailers other than semi-trailers. However, electrical braking systems conforming to the requirements of Annex XI shall be permitted. 2.2.2.3. Every trailer of category O3 or O4 shall be fitted with a service braking system of the continuous or semi-continuous type. 2.2.2.4. The service braking system shall act on all the wheels of the trailer. 2.2.2.5. The action of the service braking system shall be suitably distributed among the axles. 2.2.2.6. The action of every braking system shall be distributed between the wheels of each axle symmetrically in relation to the longitudinal median plane of the vehicle. 2.2.2.7. The braking surfaces required to attain the prescribed degree of effectiveness shall be in constant contact with the wheels, either rigidly or through components not liable to failure. 2.2.2.8. Wear of the brakes shall be easily compensated by a system of manual or automatic adjustment. In addition, the control and the components of the transmission and of the brakes shall possess a reserve of travel and if necessary, suitable means of compensation such that, when the brakes become heated or when the brake linings have reached a certain degree of wear, effective braking shall be ensured without immediate adjustment being necessary. 2.2.2.8.1. Wear adjustment shall be automatic for the service brakes. However, the fitting of automatic adjustment devices is optional for vehicles of categories O1 and O2. Automatic wear adjustment devices shall be such that after heating followed by cooling of the brakes, effective braking is still ensured. In particular, the vehicle shall remain capable of normal running after the tests conducted in accordance with Annex II, point 1.3 (Type I test) and Annex II, point 1.6 (Type III test). 2.2.2.8.2. It shall be possible to easily check the wear on service brake linings from the outside or underside of the vehicle, utilising only the tools or equipment normally supplied with the vehicle; for instance, by the provision of appropriate inspection holes or by some other means. 2.2.2.9. The braking systems shall be such that the trailer is stopped automatically if the coupling separates while the trailer is in motion. However, this requirement does not apply to trailers with a maximum mass not exceeding 1,5 metric tons provided that the trailers are fitted, in addition to the main coupling, with a secondary coupling (chain, cable, etc.), which, in the event of separation of the main coupling, can stop the drawbar from touching the ground and provide some residual steering action on the trailer. 2.2.2.10. On every trailer which is required to be fitted with a service braking system, parking braking shall be ensured even when the trailer is separated from the towing vehicle. It shall be possible for a person standing on the ground to actuate the parking braking system; however, in the case of a trailer used for the carriage of passengers, it shall be possible to actuate this braking system from inside the trailer. The expression ‘actuate’ also covers the action of releasing. 2.2.2.11. If the trailer is fitted with a device enabling compressed-air actuation of the braking system, other than the parking braking system, to be cut out, the device shall be so designed and constructed that is positively restored to the ‘at rest’ position not later than on the resumption of the supply of compressed air to the trailer. 2.2.2.12. Trailers of categories O3 and O4 fitted with a two-line air supply system shall satisfy the conditions specified in point 2.2.1.18.3. 2.2.2.13. Trailers of categories O3 and O4 shall be equipped with anti-lock systems in accordance with the requirements of Annex X. 2.2.2.14. If trailers not mentioned in point 2.2.2.13 are fitted with anti-lock systems, they shall comply with the requirements of Annex X. 2.2.2.15. The auxiliary equipment shall be supplied with energy in such a way that during its operation, the service braking energy storage device(s) shall be maintained at a pressure of at least 80 % of the minimum towing vehicle supply pressure as prescribed in point 3.1.2.2 of the Appendix to Annex II. 2.2.2.15.1 In the event of a break or leak from the auxiliary equipment or any associated pipes, the sum of the forces exerted at the periphery of the braked wheels shall be at least 80 % of the value prescribed for the trailer concerned in 2.2.1.2.1 of Annex II. However, where such breakage or leakage affects the control signal to a special device as referred to in point 6 of the Appendix to Annex II, the performance requirements of that point shall apply.