Toyota Van brakes thump

I have a 2002 Toyota Sienna van. My garage failed to check the brake shoes as requested, so I gouged the back brake drums and had to have them replaced. Shortly afterwards, whenever I brake, in the last 2-3 seconds before I stop there is a thumping noise from the right rear wheel. It will thump a few times, maybe 2-5 times, perhaps one thump per wheel rotation. I don’t feel any pulsing in the brake pedal, and except for the noise braking seems normal. Any thoughts on why? Could this be due to the shoe adjustment being too loose, so the shoe has room to pulse inside the drum?

Yes, adjustment could be off…

Or the drum could be out of round. I had that happen on my 97 Taurus - the drums, fresh out of the box from NAPA, weren’t even that close to round. More like oval. I hadn’t even bothered to check, silly me. Replaced them with a different set and they were fine.

That drum should be removed and checked for out-of-roundness. It’s not unheard of to get a brand new brake drum that is out-of-round.

Tester