Mr. fix-it

The 160 psi valve should keep the pressure at 160 psi before entering the cooler and filter, right? The pressure of the oil coming out of the filter should be reduced by the number 4 valve listed in the Bentley before it enters the oil pump. The problem is if you have too much flow there the valve can't keep up and the result will be more flow to the pump and the main front seal. The reason that I have come to this conclusion is because after changing the seal on my cooler I tried one of the bigger filter. I had a leak at the front main seal before I change the cooler seal. When I changed to the bigger filter I had oil literally squirting out of the main seal. So I took off that filter and replaced it with one of the newer filter that are more restrictive and the leak was back to a dribble. This is why I have come to this conclusion, obviously the bigger filter was allowing more pressure to push behind the seal somehow or the leak would not have been worse with the bigger filter. If the cooler and filter do not help to control the amount of pressure to the engine then why is the valve entering that area rated at 160 psi and the exiting that area rated at 72 psi? One other question. You stated in your post that most oil filters are designed to withstand 200 psi. Then why is the valve before the oil cooler in the older system rated at 237 psi? It would seem to me that the cooler is decreasing the pressure somehow or the filters on the old system would be bursting.