Coolant drain bolt

[Lonestar4x4]

I have a couple questions for the experts. I picked up a new 2011 250 six days and was going thru the PV adjustment (wasn't off by much at all). After putting everything back together I went to put the coolant drain bolt back in and while tightening to 9 Nm the fiber washer broke. My questions are; should I get another gasket type washer or should I get a copper washer? And is 9 Nm too much for the coolant drain bolt on the water pump housing? That seems like it may be too much and I'm paranoid I'm gonna strip the housing threads.

Thanks for any input!