CDL Doubles Triples Practice Test 2026
Practice with PassPrep and review the information currently available for this exam.
Start practiceExam facts
- Questions
- Unknown · Not yet verified
- To pass
- 80%
- Time limit
- Unknown · Not yet verified
- Official exam fee
- Unknown · Not yet verified
- Retakes
- Unknown · Not yet verified
- PassPrep learning cost
- Free
Official exam or application fees may still apply and are paid to the responsible authority, not PassPrep.
Study language on PassPrep
English · 中文 · Español
Official test language availability
Unknown · Not yet verified
Verify with the official testing authority. Do not infer availability from PassPrep study languages.
Source: CDL Manual — Doubles and Triples (§7)Last verified: Unknown · Not yet verified
🎯 Practice by Topic
Pulling Doubles and Triples
Why doubles and triples need special care: they are less stable and more likely to roll over because of the crack-the-whip effect (the last trailer whips hardest), so steer gently and slow down for curves; allow more following distance and space; and converter dollies built on/after March 1, 1998 must have antilock brakes (a yellow lamp on the left).
Coupling and Uncoupling
Coupling and uncoupling doubles/triples correctly — basic to safe operation, and dangerous if done wrong: securing the second trailer, handling the converter dolly, the coupling and uncoupling sequences, coupling triples, and the key caution — never unlock the pintle hook while the dolly is still under the rear trailer (the tow bar may fly up).
Inspecting Doubles and Triples
The extra inspection items on doubles/triples (beyond the Section 2 seven-step inspection): the fifth wheels (lower and upper), air and electric lines, the sliding fifth wheel, landing gear, and the shut-off valve positions — the valves at the rear of the front trailers must be OPEN and at the rear of the last trailer must be CLOSED, with the converter dolly air tank drain valve CLOSED.
Checking Doubles and Triples Air Brakes
The extra air-brake checks for doubles/triples: the air-flow test (open the emergency line valve at the rear of the last trailer — you should hear air, proving the whole system is charged), testing the tractor protection valve (it should go to emergency, usually 20-45 psi), and testing the trailer emergency and service brakes.