Hello guys, I’m proud owner of a Smart 451 built in 2009 and I never have a little problem that I need a little help with. On the last TÜV visit a lot on the rear axle didn’t bring any braking effect, hand brake was ok. After I aired the rear brake line everything was ok again but only for a few days, after that the problem was there again. Also the replacement of the rear brakes did not bring any success. What could it be that I only enter the rear brake line air? I’m already looking forward to a few suggestions for troubleshooting, Thanks already in advance