Okay, I recently purchased a 2005 F-150 Lariat, Super Crew Cab, 2WD. It only had 62000 miles on it when I bought it and I took it in shortly after for its regular 60k service, oil change, etc and they said everything looked great, but pretty soon I would need new brake pads and rotors (routine maintenance, nothing crazy) in a few thousand miles, but not to stress it yet. Disclaimer: I don't know a whole hell of a lot about trucks.

I live in East Tennessee and drive hills, get into the mountains on occasion, so I imagine the wear on brake pads and that sort of thing is a little quicker than normal with downhills and all.

Cutting to the chase - I haven't noticed any brake noise, no squealing, high pitch scratching, nothing. However, tonight when I hit the brakes I heard a very noticeable squeaky, kind of springy noise which sounded like shocks or something with suspension. When I stand on the back bumper to test to hear the noise it doesn't happen, but only when I hit the brakes and the truck lunges a little forward with normal braking, downhill or even flat. When I lightly ease on the brakes, it doesn't happen at all. It sounds like it's coming from where the bed attaches to the cab and I can't figure out what it is....

Any ideas, suggestions, anything? Any help would be great. Thanks