hello i have a b7510 with a reciently aquired pto driven 4520 backhoe attachment. the problem i seem to have is the hoe seems to have no power it barley digs. i run the machine at around 2100 to 2400 rpm and i really am dissapointed in the lack of digging force it has. being that its third hand at least to me and definatly not new i was thinking maybe the pump is either wrong one or just doesnt work well. can anyone suggest some specs to look for in a new pump flow and psi ,id prob buy from surplus supply on here . thanks