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

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Vacuum Vent Valves













1. With no vacuum applied to the signal port, the distributor (body port) should be open to atmosphere.


2. With an applied vacuum, the distributor should be closed to atmosphere.

3. A vacuum applied to the signal port and trapped should bleed off when the distributor port is open.