BS/EN 17344-2020 pdf download.Agricultural machinery – Self-propelled agricultural and forestry vehicles – Requirements for braking.
4.1.1 For the purpose of this document, the brake, all mechanical parts of the transmission and the control device, hereafter called ‘braking equipment’ shall not be regarded as liable to breakage if they are amply dimensioned, readily accessible for maintenance and exhibit safety features at least equal to those prescribed for other essential components (such as the steering system).
4.1.2 The braking equipment shall be designed, constructed and fitted, so that it is capable of withstanding the stresses arising during normal operation for which the vehicle is designated it.
4.1.3 Brake linings shall not contain asbestos.
4.1.4 Unless otherwise specified, it is not permitted to fit any adjustable valves that would allow the performance of the braking system to be changed by the user of the vehicle such that, in service, it falls outside the requirements of this document. An adjustable valve that can only be operated by the manufacturer through the use of special tool or the provision of a tamper proof seal or both shall be permitted provided that the user of the vehicle is not able to adjust this valve, or that any user modification is readily identifiable.
4.1.5 For Class IV vehicles, the wear of the service brakes shall he compensated by means of a system of automatic adjustment. In addition, the control device 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.
4.1.6 It shall be possible for the wear of the service brakes to be compensated by means of a system of manual or automatic adjustment. It shall be possible to easily check this wear on service brake linings from the outside or underside of the vehicle, utilizing only the tools or equipment normally supplied with the vehicle, for instance, by the provision of appropriate inspection holes. Alternatively, acoustical or optical devices warning the driver at his driving position when lining replacement is necessary are acceptable.
4.1.7 The requirements of point 4.1.6 are not applicable to oil immersed brakes which are designed for a long life in the vehicle without servicing.
4.2 Functions of the braking system and the basic requirements
4.2.1 Service braking system: It shall be possible to graduate the service braking system action. The driver shall be able to achieve this braking action from his driving position without removing his hands from the steering control device or with one hand on the steering control device and the other on the stepless drive control device. The service braking system can be one of the following braking systems, as declared by the manufacturer:
4.2.1.1 In the case that the manufacturer declares the stepless drive to act as a braking system, it shall not be possible to disconnect the transmission between the engine and the drive wheels during on- road use, in order to ensure that the stepless drive maintains its braking capabilities. This shall not apply to the presence of an inch device.
4.2.1.2 However, to facilitate vehicle recovery, the operators manual shall outline how to tow the vehicle without the risk for damage to the stepless drive. If a dedicated tool is needed for this purpose, it shall be carried on the vehicle.
4.2.1.3 The control device of the stepless drive shall be made in a way that inadvertent change of direction is prevented.
4.2.1.4 It is allowed to automatically engage the parking brake system at the end of the brake cycles in order to bring the vehicle to a stop on a gradient or in the event of residual creep.
4.2.1.5 In case of a combination braking system it is allowed to use simultaneously two controls in order to achieve the required braking performance.
4.2.2 Secondary braking system: The secondary braking system shall make it possible to halt the vehicle within a reasonable distance in the event of a failure of (part of) the service braking system. It shall be possible to graduate this braking action. The driver shall be able to obtain this braking action from his driving seat while keeping at least one hand on the steering control device. For the purpose of this requirement, it is assumed that not more than one failure of the service braking system can occur at one time.
4.2.3 Parking braking system: The parking braking system shall enable the vehicle to be held stationary on an up or down gradient even in the absence of the driver, the working parts of the braking system being then held in the locked position by a purely mechanical device. The driver shall be able to achieve this braking action from his driving seat.
4.2.4 The service, secondary and the parking braking systems 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, such disconnection shall be required in the case of the parking braking system actuated by a spring, in order to allow retrieval of the machine in a recovery situation.
4.3 Axles sublect to braking
4.3.1 On Class I, II and Ill vehicles the service braking system shall act on all the wheels of at least one axle.BS/EN 17344-2020 pdf download.