Cat Dealer

On the threads? Bolt seized and they broke the head off?

 

That kind of thing is common on bolts in A/C aluminum parts. Wonder if the factory uses anti seize?

 

A steel bolt in aluminum is notorious for freezing up after a few years or even months especially where moisture is concerned.
One way to break it free before you break it off is to heat it, but a lotta tech’s don’t take the time or don’t know. But if you think they were lying I really don’t think so.

 

The corrosion would be down inside the threads. More than likely enough to seize the threads up but not enough to actually see until the bolt was out (stripped threads and all).

I doubt it was overtightened. Aluminum is soft and more than likely it would have torn the threads out before the head snapped off.

That's the nature of the game unfortunately. Stuff breaks. Aluminum and steel is a stupid combination. The odds are good that bolt would have snapped regardless of who worked on it or what shop you took it to. I don't really see it being fair for the shop having to eat that cost.

 

Its hit or miss. I've snapped the heads off bolts with a quick blip of the impact, other times I've hammered on them with no issue. Anti-seize is always a must with 2 dissimilar metals in contact.