I would hear the sound under hard braking just before coming to a complete stop - just before the suspension settled. I did not feel anything thru the brake pedal. Also, I was braking hard but not hard enough to trip the anti-locks. If memory serves, I think that when the anti-lock feature is engaged on most vehicles the brake pedal will pulsate. The groan sound was loud enough that people standing away from the truck (on sidewalk) could hear it.
I should add that the noise is not why I got rid of th H3. I loved the H3
and would have continued to drive it for many years - noise and all. After owing it for a year, I had the opportunity to purchase a new H2 SUT at a very good price.
I have found the H3 and H2 to be two very capable but very different vehicles.