What happens if you over torque head bolts?
What happens if you over torque head bolts? When you overtorque above 15% of recommended which in this case would be about 95 ft/lbs you basically turn the fastener into a rubber band. Some of the fasteners will stretch and you will have uneven torque .
When to inspect and never reuse head bolts?
Always Inspect all head bolts to make sure they are in perfect condition. Dirty or damaged threads can give false torque readings; as well as decrease a bolt clamping force by as much as 50%!
Can a head bolt be stretched a second time?
If a head bolt has NOT been subjected to excessive torque; it is most likely reusable a second or even a third time. Determining which bolts have been stretched requires no special tools other than sharp eyes.
Can a head wrench break for no reason?
Consequently, Head Bolts can break for no apparent reason leaving you with a leaking or blown head gasket. Many people never check the accuracy of their torque wrenches.
When do you re torque the head bolts?
Tighten each head bolt in the same sequence as before while the engine is still warm. If the engine has an aluminum cylinder head or block; however, do not re torque the head bolts; until the engine has cooled back down to room temperature.
What to do if head bolts need retorquing?
If a gasket requires retorquing after initial installation; run the engine until it reaches normal operating temperature (usually 10 to 15 minutes); then shut it off. Tighten each head bolt in the same sequence as before while the engine is still warm.
What happens if a head bolts bottoms out?
A bolt that bottoms out will apply little or no clamping force on the head; which may allow the gasket to leak. To compensate for resurfacing; you may have to install hardened steel washers under the bolts to raise them up; or use a head gasket shim to restore proper head height.
How to tighten engine bolts the right way?
1 Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm 2 Apply a 90 degree rotation to all bolts in the proper tightening sequence 3 Apply a further 90 degree rotation to all bolts in the proper tightening sequence