Bad Brakes or Re-alignment?
 

Have an 03 Tahoe, 120k miles. I noticed recently when braking it is not very smooth. It's not like a grinding as it is not consistent, its almost like the rotor is warped or like there's a "lump" on the rotor. So hard to explain. Have replaced rear brake pads fairly recently and they look fine, front ones could be replaced soon but they aren't completely worn. I am not the original owner and you can tell that the owner before didn't know that brake pads on vehicles needed to be changed because the rotors have some wear and tear. I have had this truck for about 9 months now and this only started happening about a month ago. I'd say maybe it needs a re-alignment but not sure that it would only happen when braking if that was the case. I'll try throwing some new brake pads on the front to see if that makes any difference, anyone else experience this or have an idea what it could be?

...vague description

if there is a shimmy or shake when you apply the brakes; it probably needs rotors.

any noise or shake that occurs when braking is brake related and not alignment. a pull when braking however may mean worn suspension components or a brake problem.

Consider replacing caliper hoses as well, I have having an issue with a rear rotor/caliper on my 07. Its fine till it gets hot from use, then it acts just like a warped rotor ( which it probably is) but I suspect the hose has collapsed and the caliper starts to drag.

Appreciate the feedback! @tech2, I know it's vague, though it is hard to explain. It's not so much a shake but more of a slight bumping about once every rotation. @in2pro Ah, now that you mention it, it does seem to happen after it gets hot. I will try the hoses!

Thanks!

Go to RockAuto and order new rotors and ceramic pads if you decide to tackle that job. I haven't found parts cheaper than that. What you're describing sounds like warped rotors and is as common as cornbread.

I will add that if you do have warped rotors make sure you are using a torque wrench to tighten the lug nuts... just cranking them down without using the correct torque spec will cause premature warping...
on the 07 Tahoe the spec is 140 ftlbs... You can get an inexpensive torque wrench from Harbor Frieght... yes the HF ones may be "cheap" or less accurate, but what you want is neighborhood accuracy within a lb or so....
never use an air tool to tighten the nuts, only loosen...

Oh for sure! I have a torque wrench handy so I will be using one. Also, if they are warped, I assume I would actually be able to see the bend? Or could it be so subtle that it is not really noticeable to the eye?

0.004 thousands of an inch is pretty hard to see...so no.