What causes brake groan?

My new to me '15 Ram 1500 suffers from terrible brake groan. It only makes the sound when coming to a stop or creeping forward while using the brakes. I've driven other vehicles that had brake groan before but my truck has the worst I've ever heard. I'm guessing it still has the OEM brakes since it only has 32k miles. I did notice a ton of brake dust buildup on the wheel hoops when I bought it. Braking performance doesn't seem as good as it should be as the initial bite seems soft. From a quick look at the rotors, I don't see any excessive wear or heavy grooving on the rotor surfaces.

Could the pads be glazed? Or does it sound like they are just worn? I bought some inexpensive Raybestos EHT pads to try and see if there is any improvement. I'll swap the rotors out if I find that they are more worn than I thought.

I want to eventually upgrade the brakes with some performance pads and rotors but for right now I just want the noise to stop.

I'd check all the slides.    are the thin sheet metal shims still there and lubricated?      Are the caliper pins seizing?

Bad puns?

1988RedT2 said:

Bad puns?

Would those be... braking bad puns?

Loud brakes save lives. Won't someone think of the pedestrians!

Slider pins would be my guess.

My 16 ram came with the factory feature of one slider pin on the LF caliper and one slider pin on the LR caliper not being lubed, leading to seizing and early pad and rotor death.  I'd suggest checking those because while I love my truck for the cummins, FCA's quality isn't what I would generally want in something brand new with a sticker price of roughly 55% of my house

Rotor finish can have a lot to do with it.

GM W-body cars were particularly bad for it.