2024 WA CDL Practice Test: Class B - Test 4 Based on 2024 WA CDL Handbook 18. Air pressure should build up in a single air system, within how long? A 12 minutes B One minute C 3 minutes Next More 18/29 Progress 0 Errors Restart Next Next Class B - Test 4 Back to Test List Class B - Test 3 Class B - Test 5 Challenge Library 12 More WA CDL Practice Tests 13 Class B - Test 5 14 Class B - Test 6 15 Class B - Test 7 16 HazMat - Test 17 HazMat - Test 2 18 HazMat - Test 3 19 HazMat - Test 4 20 HazMat - Test 5 21 HazMat - Test 6 22 Passenger - Test