My 060 Bachmann loco leaks smoke fluid but I don't believe I have overfilled it. I just noticed it a couple of days ago when the bottom of the loco was sopping wet with fluid. Is this considered normal? The smoke unit doesn't glow red like it did when new a few months ago. It won't smoke unless it is almost wide open, much too fast for scale operation.
Your smoke unit may have burned out. As an aside it is not very realistic anyways, it is hard to come by realistic smoke in HO scale and generally you need to run the unit at full speed to get it to work.