T035 oil pressure

[Cougsfan]

My FergusonTO35 standard diesel has 21 hours on it since a major overhaul. The thing runs like a top, but has one concerning issue. When the engine firsts starts it has 60 psi oil pressure. Once it is running it slowly starts to drop . After 15 to 20 minutes of operation it falls all the way to 15 psi and stays there.

I put 10-40 Dello in it originally, and changed it to straight 30W to see if it would help, it didn't.

Seems like the drop in pressure is way to much to attribute to reduced oil viscosity at temperature. Its like a hole somewhere in the oil system opens up when it gets hot. Any ideas on where to look?

 

[PoorPlowboy]

What did you set the main and rod bearing clearances at? The straight 30w has lower viscosity at op temperature than the 10w-40 so the problem will not be helped. To do what you're desiring, try 20w-50 or a straight 50w.