MGM16018 brake ??????????????

I've ran my MGM 16018 in a convert truggy for a long time with mechanical brake, but now, i've put it in my new e-revo, so i don not having choice to run it with motor brake, but yesterday night, i've setup my controler and try the truck, but the controller don't want to brake. When i hit the brake , it's like if the motor fall in neutral, it's like another "freewheel", but without any brake.

I've the 3.21 sw in the controller, i'am setup in car mode brake/forward, and the brake seting is set at .23ms if i remember well.

Is somebody could help me please??

Thank you!

David