CLP Combination Vehicle Operations 3

Question 1

What does a 'glad hand' connection do on a combination vehicle?

Accepted Answer

Connects the air lines between the tractor and trailer

Answer

Glad hands are the air line connectors that join the tractor's service and emergency brake lines to the trailer.

Question 2

Why is it important to check that the sliding fifth wheel is locked in position before driving?

Accepted Answer

An unlocked fifth wheel can slide and shift the load, affecting steering and braking

Answer

If the fifth wheel slides unexpectedly, weight distribution changes dramatically, causing dangerous handling and possible loss of control.

Question 3

When making a right turn with a long combination vehicle, why should you swing wide to the left first?

Accepted Answer

To give the rear trailer enough room to complete the turn without riding up on the curb

Answer

Long combination vehicles off-track severely, so swinging wide before turning gives the rear axles the turning radius they need to avoid the curb.

Question 4

What is the function of the emergency (supply) air line in a combination vehicle?

Accepted Answer

It charges the trailer air tanks and triggers emergency brakes if it ruptures

Answer

The emergency line keeps the trailer spring brakes released when pressurized; if it breaks or disconnects, the spring brakes automatically apply.

Question 5

How far should the landing gear be cranked down when uncoupling a trailer on a firm, level surface?

Accepted Answer

Until it just contacts the ground and the weight is transferred off the fifth wheel

Answer

The landing gear should bear the trailer's weight before uncoupling so the trailer is stable and the fifth wheel can be released safely.

(CLP) Commercial Learner's Permit Practice Test