I was torquing head bolts wrong for years until a Cummins tech in Boise called me out

I always did the final torque pass in one smooth pull, thinking it was fine. This guy watched me do it on an ISX15 and said, 'You're not letting the gasket settle, you're just stretching the bolt.' He made me do it in three small steps with a 30 second wait between each. The difference in the final reading was crazy, like 15 foot-pounds off. How many other 'standard' procedures have we all been doing wrong forever?

3 comments

3 Comments

vera68122d agoMost Upvoted

Guess we all need a Boise guy, lol.

rubyk8622d ago

What even is a Boise guy? Like a guy who fixes your car for cheap? Or the one who always has a fishing story. My neighbor is from there and he can grill anything. Seriously, he made a good burger out of stuff from my empty fridge. Maybe it's just a guy who knows how to fix things without making a big deal about it. We definitely need more of those.

shane65521d ago

Man, that's a scary thought. So the whole "torque to yield" thing we hear about, is that basically what you were accidentally doing by not waiting? I've always wondered if those procedures are just for the factory or if we should actually follow them in the shop. Makes you question every single torque sequence in the manual now.