341 Bobcat boom function not working unless you deadhead another function

[robbie70]

I've got a 341 Bobcat that the boom function will not respond unless you bottom out another function and it will start working. I've changed the boom valve section of the hydraulics and nothing changed. All other function are working fine.
Has anyone ran into the problem?

 

[KOBE STEEL]

I believe these machines had a load sensing pump and control valve system. you may a faulty pressure compensator spool in the control valve. Check to see if the load sense pressure increases at the pump when operating the boom function.