Check air cleaner vacuum system integrity. Service or replace as required.
Remove items necessary to see valve door.
Check valve door for sticking or binding by depressing with fingers and
allowing internal vacuum motor spring to return door to normal position.
Correct any sticking or binding before proceeding with test.
Using an external vacuum source, apply a minimum of 54 kPa (16 in-Hg)
vacuum-to-vacuum motor and retain. The vacuum motor should remain closed for 60
seconds. If not, replace vacuum motor assembly.