Vaccum leak? Help!

I took my car in for service to fix a coolant leak a couple of weeks ago, and have been wondering ever since if they did something to cause a vaccum leak. Before I took my car in, I always read 20-21 lbs of vac at idle and when coasting down in gear. I never watched my guage while pumping the brakes before the service. Now, my car reads anywhere from 16-18 at idle, goes up to 20 when coasting in gear, and gets as low as 10-12 pounds with pumping of the brake pedal at idle.

Anybody know if this definitely means I have a vaccum leak, or if not, what a sure way to tell would be? Also, is there an easy way to find the source?

Thanks in advance, any help would be greatly appreciated!

maybe

Surely somebody here can help me. Bump for help!

C-Bass said:

Surely somebody here can help me. Bump for help!

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bov in the brake booster line ? pumping the brakes might open the valve.
mine does it a little also . i wouldnt qoute me on that tho , but ive checked pretty damn good for leaks and have never found one.