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

Vacuum System Leak Test

Fig. 4 Component Diagram:




Refer to component identification diagram, Fig. 4, when testing for vacuum leaks.
1. Remove trim panels and covers necessary to access throttle control element, near throttle pedal.
2. Disconnect vacuum line at pump and plug.
3. Hold down brake pedal to open vacuum vent valve.
4. Push in throttle control element diaphragm in and hold while releasing brake pedal to close vacuum vent valve.
5. Release throttle control element diaphragm, element must not move.
6. If element moves, repeat above test after isolating each component and circuit until leak is located.