1990 244 - 208K on the clock

I am hearing a new sound coming from the area
of the right rear wheel. It is a wuh, wuh, wuh type
sound much like a tire that is really out of balance.
Here is the weird part - you only hear the sound
when braking from 65MPH down to 25 MPH.
You do not hear the sound when accelerating and
you do not hear the sound when slowing down
"coasting" The only time it occurs is when the
brakes are applied. I have not had brake problems
recently, the car received new brakes at 198K

Any ideas?

Thanks in advance!

PS - I just completed my first 240 heater fan replacement
this afternoon - what an improvement, definitely worth
the time.
--
1990 240DL - 204K, 1989 Ranger 241K, Gone but not forgotten 1994 855