Vacume leak?

[stefan]

When the car is idling, when i press on the brake the engine idles down much lower. is this a symptom of vacuum leaks?

[miami man]

could be at the brake booster. the old way years ago is to have the moter running and spray gumout around the booster and hose and see if the engine rpms change but i do not know if you can do it these days.

[FestYboy]

that's still an acceptable method of finding vac leaks, though i find using starter fluid to be more effective as it makes the engine race more diffinatively (sp) than carb spray and thusw you can't confuse the rpm change with the IAC trying to compensate for load at idle or temp change.