A device used for controlling brake fluid pressure includes a plunger pump, for pressurizing brake fluid, and a drive motor for driving the plunger pump. The plunger pump and the output shaft of the drive motor are coupled together so as to transmit power through a cam mechanism arranged in a motor cam chamber. The motor cam chamber is provided with a communication passageway to allow brake fluid seepage to flow from the motor cam chamber to an interior chamber such as a solenoid chamber and/or one or more spring-enclosing chambers. The motor cam chamber is sealed from the exterior and brake fluid seeping into the motor cam chamber is contained within the interior of the device used for controlling brake fluid pressure.