I smoked the lower idler pully on my 99 f150 (4.2l) and replaced the pully (5 min) and have tried to replace the seropentine belt. my problem is I can't move the tensioner to let off the tension to replace the belt. I have a 15mm socket and a johnson bar on it but and am applying enough pressure to start to strip the bolt head. Tensioner wont budge (I am turning counter clockwise). Is this a common problem? Can it be ubseized or do I have to replace the whole unit?
I'm not familiar with your particular belt tensioner, but most Fords are the same. You don't turn the bolt in the center. Somewhere around the circumfrence of the tensioner there should be a little square hole. You put a 3/8" drive in that hold and release tension from there.
Ok, I looked at a picture of one online, and I'm still unsure. Either way, put the wrench on the pulley bolt, not the bolt that holds the tensioner to the bracket. If it doesn't move, replace the tensioner.