Eagle trailer/Any trailer ??'s

[prov1900]

Jacked up the trailer today to switch out oil on my dual axle Eagle (oil bath system). The back tires, i.e., the ones where the brake discs are, squealed when I spun them. They also seemed a little under pressure, obviously. I don't believe that it is a bearing issue, it's the brakes...right? Anyway, what is the issue and is this something I can take care of myself? Any help is always appreciated.

[CabinBoy]

Are they electric or surge brakes? If they are surge, they are maybe engaged if you backed your trailer when you last parked it.