I was probably wrong saying you should not be able to use the train brake when it's just the engine. It will activate the engine brake and the connection to the train won't be complete so it will do nothing.
What I should have said is it's not good practice to use the train brake when it's just the engine. You would just use the engine brake only.
As a non-train driver these are only assumptions of course.
IL2, FSX, ROF, SOW, Cliffs of Dover...
Vista Ultimate 64bit. Core2Quad9550 @ 3GHz, Nvidia 560Ti 1GB @ 1920x1080P, 4GB RAM, Creative SB X-FI