Home › CDL Practice Tests › General Knowledge Questions › Question 135
When connecting the air lines, why do you connect the glad hands with the seals facing each other and turn them about a quarter turn?
- A.To shorten the lines so they cannot drag
- B.To create an airtight joint that locks the two halves of the coupler together
- C.To drain water out of the lines
- D.To color-code the lines automatically
Correct answer
B. To create an airtight joint that locks the two halves of the coupler together
Why
Glad hands seal and lock by being pressed together and rotated, and a poor connection leaks air the trailer brakes depend on. Crossing the lines is also a real risk, so drivers confirm service to service and supply to supply by color and by testing the trailer brakes afterward.
Manual topic: Combination Vehicles - Air Lines · From the General Knowledge practice bank (GK-135).