Tighten idler arm bracket on deck or keep slightly loose?

I somehow missed the repairclinic.com video that is also on Youtube because I was concerned about the bracket I bought and not a spring I didn't know about! The video is listed as Craftsman Riding Mower Deck Return Spring 533401971 . Unfortunately the welded bracket on my deck does not have the hole for one end of the spring. Maybe it was adapted to not need one. I'm buying one anyway and will hook one end of spring to other side of welded bracket that does have a hole and will slightly loosen the bracket screw so there is a bit of movement to allow for the spring to move the brake back in place. I really wish the model you buy would match the user manual you get with the product! I'm fairly sure there never was a spring, but then the brake would always be pushing against the pulley so that doesn't make sense.

Update: with my Craftsman lawn tractor deck model purchased end of June 2010: although my manual says the idler arm needs a return spring, this is not the case. Once I attached bracket and tightened all the way, I noticed it has a special screw like a spacer that allows for some give on the idler arm bracket and the spring was no longer necessary. So- I'm good to go until the next crisis. Although I like this lawn tractor and they all have issues ... it means one different repair for every 3-4 lawn cuts. I have a tow behind Agri-Fab utility trailer that I love and just ordered an Agri-Fab 44" lawn sweeper that I'm more excited about! No more raking 25 trailer loads of clippings.