Weird Brake Pedal Thumping - Suggestions Needed

1994 Mighty Max 2.4

I just started noticing this oddity a couple weeks ago and haven't been able to figure it out.

Sometimes when depressing the brake I feel a suppressed thump/pop through the pedal. It only seems to happen at slow coasting speeds (red lights), and even then it is not a continuous occurrence.

I rebuilt the front end suspension (tie rods, ball joints, struts, etc), as well as the brakes (pads, drums, calipers) within the last year. Everything seems tight at first glance, except for a torn ball joint boot (irritating).

Any ideas what this might be?

Check the caliper mount bolts and the pins one might be loose or a pin could be sticking.

Thanks!!! Turns out one of the upper pins needed some lube.