Download CDL Prep app now

Scan QR code or get instant email to install app

Question:

Before supplying air to the air tanks of a second trailer, what do you need to do first?

A Open the shut-off valves at the rear of the first trailer and close the shut-off valves at the rear of the second trailer.

explanation

Open shut-off valves at rear of first trailer (and on dolly, if so equipped). Close converter dolly air tank petcock and shut-off valves at rear of second trailer. [Commercial Driver Handbook]

Explore more questions

Take more free practice tests for other CDL topics with our cdl prep app now!

Related Information

Comments

<img alt="" data-src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" class="lazyload" src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" /><noscript><img src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" alt=""/>

Alkam 2126

4 years ago

It a great app to study for your CDL tests

<img alt="" data-src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" class="lazyload" src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" /><noscript><img src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" alt=""/>

Cbow33

4 years ago

Great app

<img alt="" data-src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" class="lazyload" src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" /><noscript><img src="https://secure.gravatar.com/avatar/f79cda84d2c4b7b363385b30bb67cb0f?s=64&d=mm&r=g" alt=""/>

Livvy2u

4 years ago

Mom

Leave a Reply Cancel reply