Home › CDL Practice Tests › Combination Vehicles Questions › Question 16
How can you help avoid crossing the air lines?
- A.Use the color coding and matching gladhand seals and dummy couplers: supply is normally red and service is blue
- B.Connect whichever hose reaches first
- C.Mark both lines the same color
- D.Remove the seals so they fit either side
Correct answer
A. Use the color coding and matching gladhand seals and dummy couplers: supply is normally red and service is blue
Why
Manufacturers code the lines to prevent this error, red for supply and blue for service in the usual arrangement. Matching colors and checking seals makes the right connection the easy one.
Manual topic: Combination Vehicles - Coupling · From the Combination Vehicles practice bank (CV-016).