have a hard steering issue the customer ran the hyd fluid level low enough to cause the fluid to burn and smoke. So far the orbital and steer cylinder seals have been replaced and the steer pressure adjusted to 850 psi not sure what the spec is for that? We are looking for the location of a priority valve but can not find one the main control valve on this unit has two adjustments main and steer relief. The dealer says it doesn't have a priority valve? any ideas? s/n is A809N10488X thanks