A couple of times (too often) I have had to uncable the brake and use it as a better lever than the hex key,It seems logical, since they spend their lives in wet countries immersed in salty muddy water and eventually they rust and expand and get stuck down the hole..... grrrr.
Simple solution - fix a piece of weatherproof tape over the recess (something like helicopter tape) to form a patch so the water doesn't get in - that's the recesses at the back of the bolts AND, if there is one, under the front fork crown.
Works for me
Rob