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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Heater Control Valve: Testing and Inspection

Water Control Valve

- Apply a vacuum to valve. Observe movement of linkage. Should maintain vacuum until released.
- In full heating mode, feel both inlet and outlet hoses for equal temperature.
- Vacuum supply pipe color code = Red at inner vacuum switch on camshaft
- No vacuum in fully open position.