Trucks & Trailers - Hitch assembly advice needed

So here's the hitch ... 12#K monster
http://i884.photobucket.com/albums/ac47/danfab2/DSC05670.jpg

I'm converting to disc brakes and adding a reversing solenoid so I'm replacing the master surge cylinder. Question for you tow-boys, should the reverse solenoid relieve to the middle of the master cylinder where it is constnatly immersed in brake fluid or should it relieve to the top of the master cylinder?
http://i884.photobucket.com/albums/ac47/danfab2/bravo01-3.jpg

http://i884.photobucket.com/albums/ac47/danfab2/bravo03-1.jpg

One more question ... inside the hitch are two very large steel rollers. Do I have them assembled correctly??
http://i884.photobucket.com/albums/ac47/danfab2/bravo02-3.jpg

Maybe not the exact same actuator, but the design is the same:
http://www.championtrailers.com/Dico_mod_10_parts_dighm_gif.htm
Looks like the rollers should be on the same axle.
Never installed a solenoid before, but installing it above the fluid level should help prevent leaks. May result in some bubble you wouldn't get otherwise, but that shouldn't be a problem as long as you keep the reservoir full.

Maybe not the exact same actuator, but the design is the same:
http://www.championtrailers.com/Dico_mod_10_parts_dighm_gif.htm
Looks like the rollers should be on the same axle.
Never installed a solenoid before, but installing it above the fluid level should help prevent leaks. May result in some bubble you wouldn't get otherwise, but that shouldn't be a problem as long as you keep the reservoir full.

Thats it, thanks for helping me find the answer. Appreciate it...