Technician A says positive valve stem seals fit tightly around the top of the stem. Technician B says positive stem seals scrape oil off the valve as it moves up and down. Who is correct?

Question

Quizplus · Accepted Answer

Positive valve stem seals are designed to fit tightly around the top of the valve stem and also function to control the amount of oil that passes between the valve stem and the valve guide by scraping excess oil off as the valve moves.

Technician a Says Positive Valve Stem Seals Fit Tightly Around