Tractor Repair: IH 706 Diesel NO oil pressure, pressure relief valves, pressure relief valve

Question
Arnie,

Have an IH 706 diesel (single oil filter) with no oil pressure.  There is 9 hours operation on the last oil change, with good oil pressure the last time run.  I have a T connector running off the block with a gauge and sending unit to monitor the oil.

Upon start up after sitting a few weeks (battery problems), no oil pressure was ever came up.  I removed the oil pump and had it serviced with all new O-rings and seals.  After reinstallation of the oil pump, no joy with oil pressure.  (mechanic says pump if good).

The tractor starts fine and runs.  I did have some oil pool upon shutting down at the rear engine pan, with seepage at the front & rear of the pan.  Could the filter be blocked, or oil pickup come loose/off?  Any recommendations would be great!

Thanks!
mac


Answer
Hello,

  If the filter was blocked, it wouldn't have had good pressure the last time it ran, and suddenly now it doesn't.  It's possible the gauge is stuck and it really does have oil pressure, or possibly the oil pressure relief valve is stuck open and it really doesn't have oil pressure.  Disconnect the line for the gauge at the tee fitting and see if any oil comes out when the engine is turned over.  If so, then the gauge is not working.  There are 2 different diesel engines for this model, and the oil pressure relief valves are in different locations.  On one of them, it's located in the oil filter base, and on the other, it's on the side of the engine block in front of the side cover.  I don't think it is a mechanical failure inside the engine if it was OK the last time it ran.