It's time to replace airbags, Firestone or Air Lift

Ours were installed mid 2001, I dont remember the warranty, 2 or 5 years. I do remember if you purchased the on board compressor at the same time then the warranty was increased to liftime.

I dont know if they still offer or not. I don't know how that works-I assume most wont have the same truck that long so the average for the mfg are good, as the bags being what they are have to have a limited life.
Still, when a mfg steps up for a customer is awesome.