oil pressure

The pressure sensor port is after the filter so a plugged filter would not show excess pressure if the filter was not flowing right. Tight bearings also will not cause this degree of pressure; the relief valve is right in the pump and high pressures downline will activate the relief valve

Bottom line: 100 psi won't happen with 30 weight oil and a working pressure relief valve. The pump should be pulled and the relief valve examined. Look to see if the piston is put in backwards.