brake problem?

[77 montana scout]

Guys, due to my back being out again and not being able to get under the truck to trouble shoot I have a question. I noticed what appears to brake fluid on the inside of the right rear tire. Also noticed im low on brake fluid under the hood. Tried to get the wife to peek for me, all she could notice was a large amount of fluid building up just under the brake line on the inside of the hub. Its killing me not being able to get a handle on this. Anyone want to make a shot in the dark on what could be wrong? Brakes were next on the list of things to do anyway, If you guys have a good idea of what it might be I would like to get parts on the way if needed. I know this is extremely vague but it may be a common issue. Thanks for any help/input. Oh, tiz a 77 scout II.

[WarrenG]

It's sounds like it's a problem with the wheel cylinder itself. The leak could be coming from where the brake line goes into the cylinder, bleeder screw, or the seals themselves. Wheel cylinders are about a $10 part from any Napa or Checker.
Hope your back gets better soon, WarrenG