legacycentral bbs

Has anyone had this done on there AT. I keep reading bad stuff about it when google searching power purge from AAMCO

The 'power purge' sounds like a flush to me.

I've read to NOT flush an Automatic transmission if it has over 100K/never been done. It'll loosen up seals that may then start to leak.. It's best to just drain/refill/drive 3x to exchange the fluid.

AAMCO will kill that tran.
Do it yourself, drain, measure how much you took out down to the 1/4 cup, refill with same amount of new.

I wouldn't go for a machine flush, since it forces fluid through the transmission. However, merely dropping the pan and trying to drain it that way is a waste of time.


Pull the cooler lines, and let the transmission drain itself into a bucket while it takes in fluid on it's own. You won't push seals out that way.

Dan, just wondering, will the method you described drain and fill the torque converter too? (If this sounds like an ignorant question it's because I am ignorant about ATs. )

Eventually it would pull new fluid in. Using Dan's method requires great attention to the transmission fluid supply resevoir that the trans return line is sucking up. If it goes dry, you could cause damage to the trans.

The transmissions should have a check valve that keeps fluid in the torque converter. On some of the older transmissions I've seen the valve wasn't working, and when draining and refilling, I got almost all the fluid out of the trans, which led me to believe the check valve wasn't working.