Brakes stay applied and stabilitrak service light goes on

On my 2006 Envoy I'm having an intermittent problem. First the brakes start to get grabby. Then they don't completely disengage. Then the stabilitrak light and the stabilitrak service light light up. I've tried cleaning the ECBM ground and that didn't solve the issue. All of this started after I changing the serpintine belt and alternator.

This issue is starting to drive me nuts. Any idea what the problem could be?

The times I have had gurgling in the system, trapped air. Had to "burp" the coolant system.

Make sure the brake fluid is not contaminated with say p/s fluid,I have see these exact symptoms from this mistake. It would be seperated from the brake fluid and have an oily feel.

Agree with Max, sounds like fluid contamination. When you pull the master cylinder cap pay attention to the seal under/attatched to the cap. If it's swelled up and soft, thats a sure sign of contamination.

I am having the same issue. I checked my fluid and it is not contaminated and do not have any tripped codes. This is my wifes car and it bothers me that it may happen when she is driving. Any other ideas?

Are you checking for abs codes with an abs function scanner as a regular obd11 scanner will not pick up abs codes.