2024 CO CDL Practice Test: Class B - Test 2 Based on 2024 CO CDL Handbook 27. What part of the truck is the air compressor connected to? A Engine B Transmission C Radiator Next More 27/29 Progress 0 Errors Restart Next Next Class B - Test 2 Back to Test List Class B - Test Class B - Test 3 Challenge Library 12 More CO CDL Practice Tests 11 Class B - Test 3 12 Class B - Test 4 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