ZF6 clutch install

[Boathull]

Ok so I'm going to install a a new clutch in my truck and saw that I have two cooler lines running up to the radiator and was wondering if I pulled them off what will end up coming out? Coolant or tranny fluid? I don't need any smart ass comments on here. I just have never pulled one of these trannies yet. And if its coolant then I was going to add in a coolant filter. That's the reason I am asking

 

[Powerstroke1098]

ATF will come out, careful not to twist the lines when your loosening the fittings.

 

[Boathull]

Ok thanks for the reply. And what Atf do you recommend running?

 

[Powerstroke1098]

Mercon 5, I substitute one bottle with Lucas stops slip and have had good luck with that and I like the way it shifts. A lot of guys use high end stuff like Schaeffers and Redline, I might go with Schaeffers the next time. but its big money.