Hydraulic brakes can fail due to: 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. This questions appears in the following tests: Florida Class A Knowledge Test Florida Double Illinois Tank Kansas Tank Nevada Class A Knowledge Test New Jersey Class B Knowledge Test South Carolina Class A Knowledge Test South Dakota Class A Knowledge Test Texas Class A Knowledge Test Texas Class B Knowledge Test