Most manufacturers recommend rebuilding dampers every 10-40k miles even if they are not leaking. Not doing so will lead to poor performance and ultimately internal damage to the dampers. Periodically servicing your dampers will make them last a lifetime and keep your truck/Suv riding smooth.
$150 per shock including seals, fresh oil and nitrogen
$175 per shock for external bypass and IBP including parts
For sizes 3.0+ prices may vary*