(1999 f250 diesel 4x4) I have searched the site and can't seem to find a problem like mine so I thought I may as well post mand see if any one has had the same thing happen to them.
When applying more than light pressure to the brakes there is a deep not grinding sound but kind of a groan ( almost like the warning pad on the brake pads are touching rotor) as well as a pretty heavty shutter. This started about 6 months ago and I checked the brakes then and the pads were at least %90 so i thought Ok just warped rotors and I will replace them when I get a chance . I drive this truck very little so the time has went by and the problem has gotten much worse ( i only have probably put 200-300 miles on it in that time).If you brake really hard it has a really loud groan and shook really bad but mainly when you were 15 mph and slower. Maybe i just don't notice it as much at higher speed's braking but everytime it starts the noise and shutter when you are about to stop and the harder you press the more of both. If you press really hard and come to a stop and immedityl get on the gas it shutters more as if it's the tranny. It only does this for 5-10 feet and then no shutter.
Replaced new brakes and had rotors turned but it is the same no differance. Checked and cleaned calipers and the are not sticking.I hope this isn't tranny related , the rest of the time the tranny seem's to be very strong.I did see one idea that maybe the hydro booster was bad and it was not giving consistant vacum pressure . Any idea's would be great.
Jon

 

Do you have four wheel anti-lock brakes? If so you may need to get a scanner put on it that can read ABS problems.
May be worth posting this on the Superduty page in case someone there has had the same problem.

 

Could a hub assembly's bearings be on their way out? Could the wrong pads be installed, either wrong size or with a lining that is too hard or too soft, causing them to chatter?

 

It only has rear anti-lock brakes. The original pads that the truck came with worked for no problems for the 5000 miles I have driven it in the last 3 years, up untill few months ago. So i don't think that would be the problem. It also seems to be binding up about %50 of the time when you fisrt put it in reverse an start backing up slowly. Could it be a bearing issue.seems weird it only shakes stoping though.