After a regular oil change the truck died towed back to the shop found no lop after asking some questions i replaced aftermarket oil filter and cap with oem cranked for ten seconds or so then started test drove truck brought back in to check a oil leak complaint now truck wont re start no hpo this time pressure tested with valve covers off no leaks found but system wil not hold pressure leaks down very fast does this system hold pressure or will it leak down if so possible hpop fitting?

 

Could be the branch tube adapter (STC fitting), or it might be a trashed IPR from the incorrect filter. Pull the IPR, and if the screen is trashed that's the problem; it's hanging open and preventing the HPOP from building pressure. If that's the case you'd have to replace the mesh screen under the oil cooler too.

Do you have any way of checking injector control pressure and IPR duty cycle? A ScanGauge can pull these values for you, it's a great investment if you don't have an OBDII scanner that can do live data feeds:
http://www.amazon.com/ScanGauge-Auto.../dp/B000AAMY86

 

Moved to the 6.0L Power Stroke Diesel forum.

 

I only have 30 psi of icp duty i forget what duty cycle was the ipr is new replaced when it first died. Iam in the process of replacing stand pipes injector o rings and stc fitting i will check the screen when i remove the cooler it has a leak around the cover also.