[racer_d]

Take a moment and walk around the car, pushing each corner of the car down a couple of times and take note of the response.. Slow? quick? Firm? Oscillates a bit? You could also jack up the car and remove each wheel and look for signs of shock failure (like obvious fluid leaks).

While extreme amounts of dive towards the front, under braking, could be a sign of shock/spring limits, it could also be that you are braking harder than before too.

Regarless... Shocks and springs are not made to last a lifetime. They are wear items (the shocks certainly more so than the springs).

Shocks and springs are a system. While I can't recall what spring rates work well with the HD shocks, it is worth considering replacing these items all at once, otherwise you will pay twice for labor (since you need to take the car apart to replace shocks and springs)... and alignment.

I would also inspect other items like Ball joints, bushings etc that can also wear out, fatigue, crack with age and abuse.