My tranny fluid is brown!

About 3 weeks ago I changed the radiator because of an AF leak. When I removed the tranny lines the fluid was a dark brown. So over the last 3 weeks Ive done 3 drain and fills.

The fluid still is coming out brown now I'm wondering if the fluid is actually making it to the rad. I plan on pulling the supply and return lines to check if there clogged. Is this my next step? or is their something else I should start with?

The fluid doesn't smell burnt and she runs and shifts fine IDK maybe I just need to do a few more drain and fills.:dunno: suggestions please

97 4.0 AW4 98000 and I've been filling it with valv HM dex/merc

a drain and fill only takes care of about 6 qts. Your transmission holds something like 18. So when you put new in it mixes with the old and changes color.

When I did mine, I put the sending line in an empty bucket and started the truck, then I just kept pouring atf in while a budy moved the shift lever around. That way it changed most of the fluid.

So I'm going to assume that the pump picks up the fluid in the pan and then pushes the fluid through the tranny then out to the rad?

Where did you disco the supply line from? the tranny? IIRC the supply is the rear line correct? Do you have to cap the supply hole when you do this?

i dont remember which one was which. I was installing a tranny cooler for towing at the time, so I just cut into the rubber line and put both ends into the bucket. and I ran my splice to the cooler from that point. If you cant figure out which is which you can do the same then put a piece of metal tube back into that spot and double clamp each end. Just make sure you keep plenty of fluid flowing in.