New Jersey CDL Doubles & Triples: Air Brakes Test 2026

On a set of doubles, the air has to end somewhere. This New Jersey CDL doubles and triples air brake shut off test is about the shut off valves at the back of every trailer and dolly, and about the single rule that trips up new T endorsement holders: the valves must be open on every trailer except the last one in the combination, where the rear valve stays closed.

Get that backwards and the trailers behind the closed valve never charge, which means service brakes that do nothing when you need them. The drill also covers checking for air at the rear of the last trailer, spotting a leaking or damaged shut off, and why this check belongs in your walk around before you leave a Turnpike yard.

The doubles and triples knowledge exam is what earns the T endorsement, and its question count is set by New Jersey, so check your New Jersey CDL Manual for the 2026 figure before you test at the New Jersey MVC.

Keep going:

• New Jersey Doubles and Triples Practice Test
• New Jersey Doubles and Triples Practice Test 2
• New Jersey Doubles and Triples Endorsement Test
• New Jersey CDL Practice Test
• New Jersey Air Brakes Practice Test
• New Jersey CDL Combination Practice Test
• New Jersey CDL Pre-Trip Inspection Practice Test
• New Jersey Hazmat Practice Test
• New Jersey CDL Practice Test

Every question traces back to the New Jersey CDL Manual - skim the right-of-way and signs chapters before your retake.