[Big Cahuna]

I would think if the air lines are cracked that would be your problem. Replace them then pump up the shocks. I used to run arond 50 pounds in them and they wouldn't bottom out or scrape. I go about 325 lbs, so if that worked for me unless your shocks are totally shot, your good to go. Alot cheaper repair then new shocks.,,

 

[Big Cahuna]

Try a auto parts store. See if the have replacement valve for those portable air tanks.,,