I'm wanting to "tune-up" my transmission on this 190K car. I plan to convert to synthetic fluid. I would like to drain as much as I can, TC included, change the filter and re-fill with synth. I also am planning to use a bottle of trans-x as I've heard good things about this stuff.
Should I plan to change the fluid again shortly after the switch due to the tranny being cleaned by the synth? How long should I wait?
Will I spring any leaks by switching to synth. The tranny does not leak now.

My reason for doing this is I'm getting a bit more flare than I like and occasionally it downshifts hard on braking. I'll be checking the line from the modulator and the bowdoin (sp?) cable if the car has one. The car is subject to hi-speed 80 miles per day and I need for it to keep working this winter.

Any warnings, tips, advise greatly appreciated.

Thanks.