You might try changing the fluid a couple of times in close intervals, before changing the filter, and see if it stays a nice ruby color. Also, I would note how much fluid drains from both the torque convertor and pan the first time.

Ensure that you check the level when hot as I've noticed that they can be a little finicky about fluid level. Maybe it's because there is such a small amount retained in the pan.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )