At regular intervals, wipe the steel brake pipes clean and examine them for signs of rust or denting caused by flying stones. Check the fit of the pipes in their insulated securing clips and bend the tongues of the clips if necessary to ensure a positive fit. Ensure that the pipes are not touching any adjacent components or rubbing against any part of the vehicle; if this is observed, gently bend the pipe away to clear. Any section of pipe that is rusty or chafed should be renewed, as brake pipes are available to the correct length and fitted with end unions from most BMW dealers, and can also be made to pattern by many accessory suppliers. When installing new pipes, use the old pipes as a guide for bending, avoiding any bends sharper than necessary. The system will need to be bled once the circuit has been reconnected.