New CTS with a Service Brakes Soon light

I have a 2010 CTS and it had a Service Brakes Soon indicator the first day. I received my OnStar vehicle status report and it didn't mention
anything being out of the ordinary, and of course, the car stops.
I took it back to the dealer and they reset it and said a vacuum line might have been loose. The message was gone for about 4 hours and now it's back.
Anyone heard of anything like this? Is there a better forum for information (I would hope because it seems dead here). -- lab~rat >:-) Do you want polite or do you want sincere?
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