The vacuum pump is attached to the engine and maintains the pressure between in the outside air and the engine intake manifold. The pressure created helps run different systems like the ventilation and power braking. While there is no set time frame for having your vacuum pump serviced, ask your Service Advisor to check for leaks. If it becomes harder to use your brakes or you hear a hissing sound, chances are your vacuum pump needs to be replaced. If ignored long enough, things like power brakes, your heater & A/C, emission devices, and others may stop working. When your vacuum pump fails, your only option is to replace it. From a safety standpoint, there is a large safety risk because a failing vacuum pump can make it difficult to stop your vehicle. And from an environmental point of view, oil from a leaking vacuum pump can be dangerous to children and animals.