Which of the following service application valves is sometimes referred to by truck drivers as a trolley valve or spike?

Question

Quizplus · Accepted Answer

The trailer hand valve, often referred to as a trolley valve or spike by truck drivers, is used to apply the brakes on the trailer independently of the tractor's brakes. This allows for more controlled braking in certain situations, such as when descending steep grades.

Which of the Following Service Application Valves Is Sometimes Referred