URGENT NEED HERE. Folks, really need some help here. We have gone through the control valve assembly twice and replaced the add on valves for tilt and side shift and still have the same problem. Short of installing a completely new valve assembly we are at a loss. After replacing seals on the hyd valve assy(main, tilt & shift) when attempting to tilt back very gently the forks drop forward. Don't know if they did this before repairs. All other functions work well. When tilting back quickly they work as normal. What is causing the bypass. Is there a check valve in the main that we can replace or adjust? Thanks