2024 OK CDL Practice Test: Air Brakes - Test Based on 2024 OK CDL Handbook 8. At what psi is the safety valve set to open? A 100 psi B 150 psi C 200 psi D 500 psi Next More 8/25 Progress 0 Errors Restart Next Next Air Brakes - Test Back to Test List Tank - Test 5 All - Test Challenge Library 12 More OK CDL Practice Tests 35 All - Test 36 All - Test 2 37 All - Test 3 38 Tank and Hazmat - Test 39 Tank and Hazmat - Test 2 40 Class C - Test 41 Class C - Test 2 42 Class C - Test 3 43 Class C - Test 4 44 Class C - Test 5