2006 Toyota Tacoma brakes

I have a 2006 Toyota Tacoma with 190k miles. Recently my brake light came on & the pedal was traveling farther & gave some vibrating feedback. I replaced the front brake pads(the send time in its life) & the rear shoes(first time) all still had life in them. The rotors were only .01" less than new ones so I didn’t rplace them. now the light when out, but the pedal is still traveling too far & still giving the same feedback. I’m thinking it has to be the master power booster. Am I correct? or could it be something else?

Yes you are correct it COULD be the master or booster but it also could be air in the brake system. If it was bled when the brakes were changed, probably not air int he system. It could also be that the rear drums were not properly adjusted. Self-adjusting drum brakes don’t adjust very well. Manually adjust the rears and while its in the air, make sure that when the brake pedal is pressed ALL 4 brakes actually apply. If the rears don’t then suspect the master cylinder. It could also be a failed proportioning valve if the vehicle has one.