GMC Repair: Brakes, power booster, brakes

Question
How can I tell if the vacuum assist is malfunctioning?

Answer
Hi Dan. I'm not quite sure what the problem with the vehicle is. If you have a hard brake pedal, that is usually a pretty good indication that you have a bad power booster.If you could get back to me and explain in detail the problem with the vehicle i could be of more help to you.