78 shovel.
riding along and lost oil pressure no oil returning to oil tank pulled apart oil pump all wood ruff keys in place cleaned out reseated release valve reassembled still no oil pressure new gaskets run out of ideas can any body help me with this prob. thanks baldy

 

Check the drive & worm gear in the nose cone ? Collapsed oil line ? Seen old hard oil lines break internally and block the feed before.

 

How do the walls of the pump look (the area where the gears sit). If they are deeply grooved, it will not move the oil. The grooving is caused by metal particles being passed through the system, like metal from the primary and pieces from other parts of the motor.

 

Just a thought, are you 100% sure all the oil lines are routed to the correct ports? I've done that myself on an off day.