I have a few MTH 2 rail engines that the trucks are pushed up so close to the pilot steps, that the airlines can snag if they aren't rotated up in place when they are rotated by hand. I can't remember exactly what model they are. They have never given me a problem on the rails though.
I only noticed them when I first got them and I was installing the KD couplers on my bench. Try swinging the brake air lines up top. Also check that they are fully inserted into the air reservoirs. I wouldn't think anything has changed on the newest model's trucks?