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)

Or, hide this message: temporarily or permanently

Feedback Control Solenoid: Testing and Inspection


1. Using jumper wires, connect one terminal of solenoid wire connector to positive terminal of 12 V battery.
2. Connect other terminal of connector to negative terminal.
3. Remove rubber seal and retainer from end of solenoid stem and attach hose from hand vacuum pump.
4. With solenoid energized (lean position), apply 25 inches Hg. vacuum and time rate of leak down from 20 inches Hg. to 15 inches Hg. Leak down should not exceed 5 inches Hg. in 5 seconds, if so replace solenoid.
5. Check solenoid for sticking in down position by disconnecting jumper wire and checking that vacuum gauge pointer moves to zero in less than one second.