A tractor differs from a truck because:

1. Truck , bus and trailer reform act

2. FMVSS-121

3. CVSA Checklist

The trailer supply dash valve has:

1. A round blue know

2. An octagonal blue know

3. A yellow know

4. None of the above

FMVSS-121 law requires that the tractor's air system be protect from a trailer breakaway between 20 psi and 45 psi. This is why trailer dash supply valves in most cases are pressure sensitive.

1. True

2. False

The Haldex Modular dash valve

1. Is two dash valve in one

2. Has a built-in two check valve

3. Allows you to park the tractor separate of the trailer.

4. All of the above

The function of a tractor protection valve is to:

1. Protect the trailer's air system

2. Keeps 20 to 45 psi in the tractor's air system if the trailer should break away

3. Protect the tractor and if a non-automatic tractor protection valve is used the pressure sensitive dash valve will pop between 20 and 45 psi

4. All of the above

5. All but A

Haldex tractor protection valves:

1. Have a relay built-in feature

2. Have larger ports

3. Have a quick release feature built-in which releases the trailer brakes faster, giving additional brake lining life

4. None of the above

The hand control valve:

1. Controls the park brakes

2. Allows the driver to make a service application on the trailer, independent of the tractor

3. Is used to park

4. None of the above

The two-way check valve between the hand control valve and the foot valve seeks out the dominant pressure and sends it to the trailer's service brakes

1. True

2. False