Moutain bike brake problem



How tight should you make the bolts that hold the brake into the boss? One of the 2 brakes after squeezing the brakes does not spring back but merely stays where it is. If I back off the bolt to the boss a bit, it works fine. The spring is in the topmost position on the boss. Bad spring? Bad brake? Bolt too tight? Thanks.

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Thanks for all the suggestions. Tried them all. Then I noticed on the good side that the spring that pokes into one of the 3 tension holes protruded through the hole furthur than the other side. I reversed the spring on the bad side (which by the naked eye looked the same both ways) and presto. So I greased it and put lock tite into the post. LBS did maintenance check/adjustment on this bike in July - never again.