Skip to main content
TEST PREP
Start

Ontario Air Brake Practice · Question

If a red warning light appears on the trailer service (yellow, diamond-shaped) valve, coupled with a loss of air pressure on the secondary gauge, what specific issue might this point to?

A red warning light on the trailer service valve combined with a loss of secondary air pressure often points to a severe air leak in the trailer's service brake

Start free practice for Ontario Air Brake Practice

40 questions · no signup required · 40 free questions per day

Start Practice →

Question: If a red warning light appears on the trailer service (yellow, diamond-shaped) valve, coupled with a loss of air pressure on the secondary gauge, what specific issue might this point to?

Answer options: ✅ A severe air leak in the trailer's service brake lines.

  • The trailer's anti-lock braking system has failed completely.
  • The tractor's parking brake is accidentally engaged.
  • Over-pressurization of the trailer's air tanks.

Correct answer: A severe air leak in the trailer's service brake lines.

Explanation: A red warning light on the trailer service valve combined with a loss of secondary air pressure often points to a severe air leak in the trailer's service brake lines, as the secondary system typically powers the service brakes. This requires immediate attention.

Start free practice for Ontario Air Brake Practice

40 questions · no signup required · 40 free questions per day

Start Practice →

More about Ontario Air Brake Practice

Related Questions

More for Ontario Air Brake Practice candidates

Ready to practice?

Free, no signup required. Build a wrong-question list as you go.

Start Free Ontario Air Brake Practice Practice →

Related courses

Other Canadian certifications candidates often prepare for alongside this one.