In a dual air brake system, a leak in one system: Before you start the test, please answer the question below regarding your insurance status. Without insurance you will not be able to drive in Ohio Do you currently have car insurance? Yes I have insurance. Great, you're all set! Click here if you still want to compare rates. No, I need insurance. Click here to compare rates from our insurance partner. Question In a dual air brake system, a leak in one system: Answers Always means there are leaks in both systems. May not affect the other system. Is not something to worry about. Explanation A dual air brake system is made up of two separate air brake systems. If there is an air leak in one system, it may not affect the other. This questions appears in the following tests: California Class A Knowledge Test California Air Brakes