Practice question

A hydraulic-brake school bus has a spongy brake pedal that slowly sinks under steady foot pressure with the engine off. The MOST likely cause is:

  1. Air in the hydraulic system or an internally leaking master cylinder
  2. A worn wheel bearing
  3. A clogged cabin air filter
  4. A weak alternator

Answer: A — Air in the hydraulic system or an internally leaking master cylinder

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: ASE S4 Brakes (School Bus) Practice Questions - ASE S4 - Brakes (School Bus) Certification Exam →