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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Heater Control Valve: Service and Repair

Heater Valve (Vacuum Unit And Coolant Check Valve):





1. Open cap on overflow reservoir.
2. Disconnect coolant hoses.
3. Remove heater valve.
4. Install heater valve.
5. Open coolant bleeder screw.
6. Fill with coolant to maximum mark on overflow reservoir.
7. Close bleeder screw when coolant comes out.
8. Install cap on overflow reservoir.
9. Connect hoses to vacuum unit on heater valve.
10. Run engine until radiator fan comes on.
11. After cooling, check coolant level.