Technician A says a restricted vacuum feed hose may cause loss of assist after several quick brake applications. Technician B says brake fluid in the vacuum feed hose indicates a leaking master cylinder seal. Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. A restricted vacuum feed hose can cause loss of assist after several quick brake applications because the vacuum supply to the brake booster is decreased, resulting in reduced power assist. Brake fluid in the vacuum feed hose indicates a leaking master cylinder seal because the brake fluid has leaked past the seal and into the vacuum lines connected to the brake booster.

Technician a Says a Restricted Vacuum Feed Hose May Cause