The two markings on a front brake limiting valve usually read: Question The two markings on a front brake limiting valve usually read: Answers "Normal" and "slippery." "Low" and "high." "Left" and "right." Explanation Some vehicles with air brake systems manufactured before 1975 have a front brake limiting valve with "normal" and "slippery" settings. This questions appears in the following tests: Iowa Class B Knowledge Test Kentucky Air Brakes Louisiana Class B Knowledge Test Maine Class A Knowledge Test Maine Air Brakes Michigan Class A Knowledge Test Michigan Class A Knowledge Test Michigan Class B Knowledge Test Missouri Air Brakes Nevada Class A Knowledge Test Nevada Air Brakes North Carolina Class A Knowledge Test South Carolina Air Brakes Virginia Class A Knowledge Test Washington Class A Knowledge Test
