Morning All,

Hate to ask but have a silly question the trans fluid change/flush procedure. The 3 trucks I've done a fluid change on have all been pre-2001 so they had a plug in the torque converter. I'm about to attempt it on my "new" 02, which has no plug.

My questions is, if you're draining the fluid out a bit at a time, then refilling the same amount you put back in, when you start the truck the next time aren't you pumping out the fluid you just put in? My understanding is that when you pump it out of the cooler lines it's pumping from the pan, which is where you just put fresh fluid, which would mean I'm pumping fresh fluid.

Can someone straighten me out on this one? I hate it when I try to overthink things.

Thanks

 

It is not being pumped from the pan. Fluid is picked up from the pan and circulated through the convertor on it's way to the cooler.
When fluid exiting the disconnected cooler line looks nice and red 99% of it will have been changed.

 

Thanks Stuart. I knew I was overthinking it. The write up I read was talking about disconnecting the return line at the transmission, and when there were air bubbles in the line it meant the pan was empty.

I starting thinking about it (which is always a dangerous proposition), thus the question.