Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Vacuum Check Valve: Testing and Inspection



To check vacuum check valve, use a suitable hand held vacuum pump and apply 16 inches Hg vacuum to the check portion of valve. Maintain vacuum. If vacuum applied remains above 15 inches Hg vacuum for approximately 10 seconds, the vacuum check valve is operating properly. If not, replace vacuum check valve.