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 Gauge/Economy Meter


Vacuum Gauge:





Vacuum Gauge Readings:







^ Used to monitor the engine intake air system, while the vehicle is running.

^ Can be used to detect:

- Obstruction Of Air Flow In The Exhaust System
- Sticking Valves
- Broken Valve Springs
- Low Compression
- Ignition Timing Problems
- Vacuum Leaks