While setting relief pressure for the lift circuit on a 7fGCU25 the guage reads around 450psi then while continuing to raise relief pressure setting the system spikes up from 450psi to over 5000psi with the eng. rpm maxxed out and the lift cylinder extended, then blows the back of the pump offwithout even **** in the relief valve. Anyone else ever experience a similiar scenario? I completely drained and cleaned the circuit and reservoir, replaced pump and whole relief valve only to have the same issue repeat itself. Any insight would be greatly appreciated.