In some examples, an assembly includes a wheel configured to rotate around an axis and a brake system configured to reduce a rotation of the wheel. The brake system includes a disc stack having a rotor disc rotationally coupled to the wheel and a stator disc, wherein the wheel is configured to rotate relative to the stator disc. The brake system includes an actuator configured to compress the disc stack. The brake system is configured to exert a reaction force on the disc stack when the actuator compresses the disc stack. The assembly includes a mechanical stop configured to encounter the brake system, wherein the mechanical stop is configured to limit a linear displacement between the actuator and the disc stack.