Possible stuck slide pin or caliper. Commom hand tools should be fine.

 

Could also be a collapsed hydraulic hose or a sticking caliper. Most likely, one of those two or a combination of several faults.

 

Don't forget to check both sides. While pads continuously contacting the rotor on the left can heat the pads to a higher level of friction, the right side braking could be hampered with stuck pins or pistons not providing as much force. Hoses typically induce a hard pull, you have to determine that degree.

The thump can be a hotspot in the rotor growing in thickness or a hard spot reducing friction so you transition in braking effectiveness and bouncing the pads off the bracket. We had measured that motion of the brake pads with magnetic accelerometers on the pads themselves.

 

Purchase new rotors pads and calipers WITH their mounting bracket and those lovely NON-sliding pins. Always replace both sides. Check the rear pins and Ebrake shoes, hardware and mounting studs. Bleed the entire system front to back. Repeat Biennially ALL of it. The pins need an inspection at each tire rotation or every 100 miles whichever occurs first. My money is on the pins... search me here for more colorful details...