brakes thumpy sometimes?

I replaced my brake pads and rotors last March. They were almost immediately thumpy but only sometimes. When coming to a stop, it feels like the rotors are bumpy. But today when I stopped, the brakes felt like a dream and were as smooth as can be. How can rotors just go back and forth from being thumpy to smooth and back thumpy all the time?

I replaced my brake pads and rotors last March. They were almost immediately thumpy but only sometimes. When coming to a stop, it feels like the rotors are bumpy. But today when I stopped, the brakes felt like a dream and were as smooth as can be. How can rotors just go back and forth from being thumpy to smooth and back thumpy all the time?

sometimes oil or other fluids can leak down on the rotors.

sometimes oil or other fluids can leak down on the rotors.

Makes sense except I checked my brake fluid yesterday and it was right up on the top of the resivore. Wasn't low at all. The guy at Auto Zone made the suggestion that maybe I have a wheel bearing going out. When he said that, I didn't think it was a bad idea, but a wheel bearing I'd feel the "thumpyness" all the time and not just when I was braking.

Makes sense except I checked my brake fluid yesterday and it was right up on the top of the resivore. Wasn't low at all. The guy at Auto Zone made the suggestion that maybe I have a wheel bearing going out. When he said that, I didn't think it was a bad idea, but a wheel bearing I'd feel the "thumpyness" all the time and not just when I was braking.

I would open the bleed screw on one side at a time right front first. then using a clamp push back cal piston to remove the old fluid ..see if the cal is good no binding or any leaks/rust/seal damage. make sure the pads are not locked up. file the steel backing plate if necessary so the set into place with ease. bleed and repeat on the other side. checking the hub for issues like ruffness drag etc...

I have this same problem on my Impala 2004 3.4