CHASSIS MODIFICATIONS 2-43 E UROCARGO Euro 4/5 2.7.8 Stabilisers When pneumatic suspension is used for the added axle, depending on the solution adopted, it may be further necessary to fit an antiroll bar in particular when a body with a high centre of gravity is used. Similar measures must be adopted to ensure stability in relation to mixed type suspension on an additional rear axle. 2.7.9 Connection to the chassis frame The connections of the added axle to the chassis must be such as to be able to withstand all longitudinal and transverse stress forces without transmitting them to the drive axle.
At the points in which the forces are introduced (spring supports, air spring brackets etc.), appropriate cross members or suitable frame reinforcements must be provided. Ensure that the added axle is at right angles and aligned properly in relation to the longitudinal axis of the vehicle and the live axle. Check using the appropriate equipment available in the market. 2.7.10 Braking system for additional axle ! The braking system, considering its importance relative to the active safety of the vehicle, must be ex- tremely well developed and constructed. Braking units, hoses and joints of the same type as on the original vehicle must be used.
The auxiliary axle must be equipped with the same brake components as those provided for the front axle. Use flexible pipes to form the connection between the fixed parts (chassis) and moving parts (axles). The braking torque must be proportional to the static and dynamic loads in order to provide an even distribution of the braking action to all the axles of the vehicle. The total braking capacity of the modified vehicle must, as a general rule, be proportional to that of the original vehicle, allowing for the different total mass that is now applicable.
The performance of the braking system (service, emergency and parking) must in all cases satisfy the current government regulations in terms of deceleration, behaviour when hot, response time, efficiency of engine braking and so forth. If the Technical Control Authority demands that the technical documentation regarding the braking system be submitted (e.g. ad- hesion curves, compatibility range diagram) this must be provided by the company in charge of the conversion or the manufacturer of the auxiliary axle. Upon request, technical documentation with characteristics and attainable performances of the braking system of the original vehicle may be made available.
For the construction of the braking circuit for the additional axle it is advisable to employ equipment and circuits specially provided for each single model by the Manufacturer of the equipment in use on the original vehicles. Solutions are allowed that include direct connection between the additional axle braking section and the engine axle braking section. Check that the air tank capacity is sufficient for the size of the new additional brake cylinders. If necessary, fit a supplementary air tank. Current legal requirements must be complied with for the emergency and parking brake. We recommend that a parking brake is fitted on the additional axle.
For indications of a general nature concerning the braking system, see the instructions given at point 2.15. For the electrical system, comply with the indications provided at point 2.16. ! Installing a supplementary axle Print 603.93.431 Base - January 2008