when raising rear wheel for transport, in the control steering valve, a plug holding the poppet valve and spring, has what seems to be a soft plug in it..When I lift the plows, it blows this, what looks like a tiny copper screen, and oil blows out. I've bought 3 new plugs but keeps blowing the soft plug out. Any mechanics out there have any idea what's going on here. Been to the dealer to no avail?