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Question:

After connecting the air lines but before backing under the trailer you should:

A Supply air to the trailer system, then pull out the air supply knob.

explanation

Step 8: Supply Air to Trailer: From cab, push in \"air supply\" knob or move tractor protection valve control from the \"emergency\" to the \"normal\" position to supply air to the trailer brake system.

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Alkam 2126

4 years ago

It a great app to study for your CDL tests

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Cbow33

4 years ago

Great app

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Livvy2u

4 years ago

Mom

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