So, what's the problem with trans flush? I know that happens. It happened to my old 78 Pontiac when I had the trans flushed. A month or so later and the trans needed a rebuild. Just want to know what causes the problem?
Sometimes when they hook the machine up they do a reverse flush. Anyway, after years of heat the fluid looses all its additives and all the debris attaches to the clutches, etc and becomes should I say part of it. All that nice new detergent cleaners breaks it down and most of the friction is gone. Much better to do a simple filter and fluid swap if going to at all. Maybe just pump a quart or 2 out the dipstick and add some new over an extended period.
Some new cars you can't even check or add trans fluid. The pros call explain it a lot better than I and they use really impressive words while doing it.