The present invention is a system for adjusting the height of vehicles that have coil spring suspensions. The invention may be added to existing vehicle suspensions without the need to remove and replace the existing vehicle suspension components. The invention includes cylinders, pistons, seals, dust shields, pressure pump(s) and storage tank(s). It also may optionally include electronic hardware, such as, an electronic controller and software, to control the functions of the system and sensor(s) which detect ground clearance and speed. The invention may be operated manually by a vehicle driver through push buttons, which may operate through the vehicle's existing cruise control buttons. Alternatively, the system can be automated through an electronic control unit (ECU) to avoid collision with obstacles in the vehicle's path.