My '66 MF203 Workbull with the AD3-152 Perkins runs about 50 psi oil pressure. I got tired of the old style canister oil filter so I bought and installed the conversion kit which consisted of the adapter, gasket and spin on filter. I added 6 qts. of new oil, started the engine and no oil pressure reading on gauge. I let it idle for about 10-15 seconds and nothing, then shut it off. In disbelief, I started it again, let it idle same amount of time and still nothing. I didn't hear anything getting "noisy", so I have to believe the oil pump is still working so where's the pressure? One thing that caught my eye is that on the original adapter housing there is what I would say is a relief check ball and on the new housing, there is nothing at all.