First, pop the old pvc valve back in just in case it's allowing the crankcase to get drawn into a vacuum. Next, install a mechanical gauge to see if the pressure really is dropping. If it is, suspect chunks of RTV sealer fell into the oil drain passages and are plugging the pump's pickup screen. The clue is the pressure drops over time as the debris gradually gets drawn over to the screen.
Thursday, December 24th, 2009 AT 11:10 PM