Light duty cutaways and school busses equipped with a hydraulic power brake booster system have a warning system. This system alerts the driver to a malfunction in the hydraulic power brake booster system. The BRAKE warning lamp illuminates if the fluid flow or pressure from the power steering pump is low.

Light duty cutaways and school busses use a flow switch. The flow switch senses the volume of fluid supplied from the power steering pump. When it sense fluid flow that is inadequate, it signals the alarm module. The flow switch is located in the power steering pressure pipe near the pump.

Light duty cutaways and school busses use a pressure switch. The pressure switch senses fluid pressure entering the hydraulic booster. When the pressure switch senses that fluid pressure is inadequate, the switch signals the alarm module. The location of the pressure switch is near the hydraulic brake booster.