If I loctited the nuts that hold the cranks and I check the tightness in the future and the nut moves does the loctite still work?

Never used loctite, but seeing as no one else has replied:

No, it doesn’t. Once on it hardens. Moving the surfaces breaks the bond.

actually depending on the type of loctite that you use (some are stronger than others) it will still work but it will not be as strong as it was before so I would suggest that you put a little on the bolt after you take it off.

Once you get the nut to move the bond is broken and the Loctite is no longer doing its thing. The Loctited threads will still have some additional holding power compared to unLoctited threads, but the hold will be nowhere near what you get with the full unbroken Loctite bond.

Once the bond is broken I remove the nut or bolt completely and use a small screwdriver or similar tool to pick out the dried Loctite from the threads, then reapply the Loctite before putting the nut or bolt back on.

The thing with Loctiting the crank nut/bolt is that you do not need to check the nut for tightness anymore. Just leave it alone. If the crank was put on using a torque wrench then still going to be tight as long as the Loctited bolt has not moved. If the crank starts to have play it is going to be because the crank is either starting to split or the aluminum tapers have deformed due to heavy use. In either case the crank is probably shot.

And after my experience with my stripped coker hub I now use medium strength Loctite for the crank bolt/nut. I don’t think it was the high strength Loctite that killed the threads on that hub, but just to be safe the medium strength is the best option. Medium strength is plenty strong for the purpose. I suspect that the threads on my stripped hub were just more brittle than typical for a Miyata hub. There can be variances in heat treating and being just a little bit off in the heat treating process can make the threads more brittle than they are supposed to be.