When im approaching a stop and i start pressing the btake the rpm moves up. Whats happening?
check for a vacuum leak...
Sounds like you have a brake booster starting to fail, try this start the engine and let it idle for a bit then shut it off, when is quiet slowly step, but n the brake pedal and listen for a hissing sound, if you hear one then the booster is leaking and will need replaced. HTH
Search GMC Sierra 1500 Questions
GMC Sierra 1500 Experts