Ford Repair: Repairing 1994 F150 Tension Pully, tensioner pulley, ford f150

Question
1994, Ford, f150, 5 liter engine

The tension pully for the power sterring broke.  

How do I back off the screw that holds the pully on?

Is it metric?

Is there a back up nut?  

Answer
Hello and thanks for the question...I'll try to help.
If you are talking about the tensioner pulley nut, it should be a 16mm or 15mm. As far as replacing the pulley, you will have to turn the nut, going with the tension of the tensioner asymbly.
Hope this helps,
Erik