JLG 450A Basket Not Leveling / Going Down all the way

I have (2) 2001 JLG450A's that are twin machines. I am new to the articulating boom over the straight boom's. On one of the machines the basket will not level from the basket but will from the machine. On both machines more times than not the basket will not go all the way down via both controls (Basket/machine).
I am able to swap parts from machine to machine to troubleshoot. Any suggestions would be appreciated.

Thanks

JLG 450A Basket Not Leveling / Going Down all the way