In the process of troubleshooting my brakes I hooked a vacuum gauge up to my intake manifold to check the vacuum. When the engine is warmed up I am pulling ~12 inHG. According to the Haynes manual for every 1000ft above 2000ft you can add ~1 inHG to the reading, so now consider that I am at ~4500ft elevation that would indicate ~14.5 inHG vacuum. Haynes also says a normal and healthy engine should pull around 17-22 inHG. Should I be very conserned?

I'd like to try to find any vacuum leaks, if thats the problem. Does anybody have any tips on how to find them short of just replacing/tightening stuff? It's not like I can just spray soapy water and look for bubbles since we're talking vacuum right?

Also what effect would this low vaccum have on the brakes?

Any insight would be greatly appreciated.