Trailer Brake won’t release

Trailer is tandem axle Boatmate with surge disk brakes. The brake won’t release on 1 wheel. I have tried pressing the manual brake release button (under the tongue) but no go. Would bleeding the fluid be any help, or should I go ahead and remove the caliper? Any other suggestions? Thanks.

you probably pulled the emergency brake wire, check that

If it is only 1 wheel it may be something caught in the brake line. I've heard stories of rust getting caught in brake lines causing the calipers to get stuck closed (pressurized).

Funny this comes up now. I was at Tulloch last weekend getting ready to leave on Sunday one of the tires on my tandem trailer is locked up. Tried all the regular stuff (emergency release/hydraulic line etc.). Tried rolling back and forth over and over etc. So rolled one of the tires onto a big rock (jack) and I ended up tearing the whole thing apart. (An hour later in 105 degree weather), I get the drum off and it is exactly that. 2 spots of hardened brake dust that fused to the drum. I sand it off gently and re-set the drum and it spins freely. Funny it happened this time as I even let the brakes cool for an hour or so after the initial drive up, to unload groceries etc before launching (as much as brakes can cool in hundred degree weather). Not sure what I can do different next time, I think I just got UNLUCKY although I am open to suggestions.