I bled the brakes on an old bike that had sat for over 10 years...looked like brown mud coming out,good news is,it had brakes with new fluid.Bleeding is a good idea,especially if you ride in the rain,becuase there's no such thing as a perfect seal,and some water WILL get in no matter what.
Cheap method of bleeding,you can just do the pump squeeze,crack the bleeder screw until you flush em out too.,or use one of the 5 dollar kits with a check valve and a piece of clear tubing that you get at any auto parts store.

 

Well I wish I hadn't posted at #9 above! I have had my Glide's front and rear brakes apart recently, fitted a new rear caliper and braided pipe and it bled 'the old fashioned way' in moments. Surprised me it worked so quickly! The front end was a different matter and has really tried my patience. I eventually bought a Mityvac, which looks similar to Howard's HF but all plastic, and it helped! At long last I have two firm brakes, but have also had my best and worst bleeding experiences in one. I have a few other things to finish off then I can see if they actually work on the move!