[osikasculptor]

I bet it is because mine did the same thing and a few of us had no clue until we experienced the same thing with servos. It seemed to make no sense..pump barely running..tracks moving backwards..but as soon as the servo is replaced all normal. When you replace it..make sure to center it.
Power up then with trim on radio at zero -move the control by hand so what ever function it's on-floats in neutral..or as close as you can get it then pop the servo in. It always moves a tad because of the gear but if close you can trim it manually.