Lionel Legacy Controller Train Brake slider

Unless someone else chimes in and says othwerwise I believe it is normal. I thought the same thing initially until I realized that the "train brake" slider is used to vary the load on the locomotive, not really a brake however it will stop the train when slid all the way to the bottom. The actual "brake" is the multi switch boost/brake/ direction toggle on the right side. When your loco is running gently slider the "slider" up or down and watch the display for the load indicator on the bottom of the screen, listen to the loco begin working harder or easier.Very slight movement of the slider makes noticable changes. On a side note, the best "braking" feature is achieved by pressing the M button and setting the momentum by turning the dial. Setting the momentum at 6or 7 then bring your loco up to speed. When you want to bring your locomotive to a stop turn the throttle back to zero,when the throttle is backed down faster than the momentum the brakes will come on and the loco will come to a long grinding,realistic stop. This is probably my favorite feature next to the quilling whistle,BTW this feature only works on legacy locos.
 

Train brake is not spring loaded like your whistle control . it does slide easily.
It will slow down legacy engines and work quite well. it'll also work on TMCC engines but not as dramatic.
Another thing I like to do is set the momentum to high(Down at the bottom where you see L,M,H) just press the "H" start your engine and let it get up to 25 or 30 MPH and turn your throttle wheel all the way up. Then use the train brake to regulate the speed. If you've got grades like I do the steam engines actually will sound like they're working like crazy to get up the hill. I can't say enough about legacy sounds .
There's nothing in O scale right now that even comes close.

David

Both of my CAB2's are that way, and that's how it's supposed to work.  You can set the brake slider and leave it in a position to limit the speed and cause the labor to increase in the RailSounds.

OTOH, you wouldn't want the horn slider to stick in a position, right?

Nothing's broken, working as it should.