Question Hydraulic brakes can fail due to: Answers A loss of pressure. Cold weather. Driving uphill for long periods of time. Grooves in the roadway. Explanation Failure of hydraulic brakes is often caused by a loss of hydraulic pressure. Hydraulic brakes may also fade because of overuse on a long downgrade. Take a FREE Practice Test Now This questions appears in the following tests: New York Knowledge Test Class A , Kansas Knowledge Test Class B ,