2003 Venture - Brake problems - HELP!!!

Four months ago, I had new brake pads put on my vehicle. Today, I noticed a screeching sound and took the vehicle in for servicing. The pads are completely worn out. I was actually shown the pads. How could this have happened in only 4 months! New pads were put on and new rotors and now when I apply the brakes I hear this loud knocking or rotating sound. Please help. What is going on with my once reliable van??

It sounds like the calipers are sticking. They have a piston on one side and are supposed to slide freely enough to center themselves across the rotor. You might check the pins to see if they are pitted or otherwise aren't smooth. Replace them and grease them with lithium-based grease.

They could also be just really cheap pads. You get what you pay for.