I had my wheels off to put on some new ones the other night, and i noticed a hose coming out of the axle that looks like a brake line, but I have no idea what it connects to. My back brakes squeek really badly the first 1-2 times i apply them cold, but then run quiet and well after that (maybe a slight brake fluid leak?). I want to check the shoes again in daylight, but they looked alright to me. When I took the drum off it had some brake dust in it, but I don't know if this is normal or not. The line was wrapped up around the leaf spring, but I can't seem to figure out what it attaches to? Any suggestions on either this line or the squeek? (also, it groans a little bit in reverse with light brake pressure backing out of the driveway) Thanks!

 

That's the axle vent. It doesn't hook to anything, but should have a vent end on it. It mounts as high as possible so water doesn't get in it.