Please define re-torquing as in the example of head bolts. Do you back em off and then re torque it, or do you just have to tighten them again from where they are?

 

I was always under the assumption to just tighten them again to get the torque setting again. Who was the idiot that came up with having to retorqing head bolts anyways?I bet there isn't a garage that says:you have to come back in a week so we can retorque your bolts.

 

I have always gone with the loosen and re-torque method. I do it one bolt at a time, using a 'click' type torque wrench. As for the reason, there are several depending on the application. I have found that new head gaskets, depending on their construction, will tend to compress after a period of time. This could lead to premature faliure or leak if the bolts are not re-torqued to compensate. I would suggest you follow the manufacturers recomendation.