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 Regulator (4-Port)



Vacuum Regulator (3 & 4 Port):






1. Remove the vacuum line from the distributor port of the regulator valve, and install a vacuum gauge.

2. With the engine at idle, the vacuum gauge reading should be within 1" vacuum (3.4 kPa) of calibration point.

3. Vacuum calibration points are identified, with the different color codes:
- Black is 6" vacuum (20 kPa)
- Green is 7" vacuum (23.6 kPa)
- Red is 8" vacuum (27 kPa)

4. If gauge reading does not meet color code indicator, replace vacuum regulator.