Help please. I have a MF 220 backhoe that blew the hose on the left side of the conrol gang as you sit to operate the hoe. I replaced the hose, then the return pressure plate on the gang reptured. I have now replaced that but want to know why the pressure builds so high before I continue. When the selector valve is set to operate the hoe, the engine starts to strain, as if there is a restriction. Any help is appreciated thanks