2024 TN CDL Practice Test: Double and Triples - Test 3 Based on 2024 TN CDL Handbook 1. Usually, a fully charged air system has _______ psi. A 125 psi. B 90 psi. C 60 psi. D 100 psi. Next More 1/29 Progress 0 Errors Restart Next Next Double and Triples - Test 3 Back to Test List Double and Triples - Test 2 Double and Triples - Test 4 Challenge Library 12 More TN CDL Practice Tests 27 Double and Triples - Test 4 28 Double and Triples - Test 5 29 Tank - Test 30 Tank - Test 2 31 Tank - Test 3 32 Tank - Test 4 33 Tank - Test 5 34 Air Brakes - Test 35 All - Test 36 All - Test 2