I've noticed that my 01 has a thunk sound when I start to apply the brakes, and right as I completely let off the brakes. This only happens if I'm rolling forward at 5mph or faster, so it's hard to isolate where the sound is coming from. I can feel the thunk in the floorboard (with my left foot).

Anyone have a suggestion as to what it is? I'm going to bleed the brakes, but I don't have a lot of hope that is the cause....

 

Heres a few suggestions you may already know about:
Check the drivers side lower a-frame rear bolt, the infamous clunk in the slotted frame hole. Also, check the caliper free play in its mounting bracket.

 

Install 'clunk washers' and grease the steering stops (on the back side of the spindle) and you should solve it.

https://www.f150online.com/forums/sh...ad.php?t=74800

 

Clunk washers have been in forever... I'll check them, but if they are loose enough to slip , yikes! I'll check the brake caliper as well. Thanks.