After coupling a double, what do you do with the converter dolly air tank petcock?
Right! Close the dolly air tank petcock and the rear shut-offs of the second trailer. 📖 p. 85
From Section 7 of the Colorado Commercial Driver License Manual
Colorado CDL Doubles and Triples Practice Test
Who takes it: Class A, for the T endorsement.
Pulling two or three trailers. 20 questions, 16 right to pass (80%).
Practice Doubles and Triples
- 10questions a round
- 1manual section
Take the Doubles and Triples test
- 20questions
- 16correct to pass
- –no test taken yet
A Doubles and Triples question to try
Tap an answer to see if you’re right, and the page
Where it is in the Colorado Commercial Driver License Manual
Your score on each part fills in as you study.
- Manual section 7
- Doubles and triplesNot practiced yetp. 84 to 87
The manual says to also study Sections 2, 5 and 6 for this test, so when a practice test needs more questions than this section has, it adds some from those sections.
Colorado answers about this test
Practice material, not the official test: check every answer in your state's current handbook. Disclaimer · How the rounds work · DMV
All Colorado CDL tests
- General Knowledge
- Combination Vehicles
- Air Brakes
- Doubles and TriplesYou're here
- Passenger
- School Bus
- Tank Vehicles
- Hazardous Materials
- Which tests do you need?Pick what you'll drive and get your Colorado CDL plan, in order.