my solenoids acted quirky several years ago. it would not shift from 1 to 2. i did a drain and refill, and then again, and then again, and then again. you only get out a coupld of quarts from a ~15 quart system. by doing it and then running aroud for 15 minutes and then again and repeat, you get a lot more of the old stuff out without the power flush method. of course you lose some of the new stuff you just put in each time, but it is still worth it. my problem went away. i think a solenoid was just sticking.

Scott Landon
1995 T100 - total buildup underway
1988 4Runner (22RE, W56) - new DD
2005 Dodge CTD 4x4 - Tow Beast
1990 Spec Miata
2010 GT3
2013 E92 M3