my74 ironheadhas no oil pressure. i have rebuilt the oil pump and replaced all of the lines, still no pressure. when i fist rebuilt the pump, i cracked the housing, so i replaced it, but with the wrong one, so i had too much pressure, put on another correct housing and i had pressurte at first, but i slowly lost pressure and now have none at all. anyone have any ideas of what is going on here. any help is appreciated. thanks.
-mike

 

To begin I have to ask.....What is telling you that you have no oil pressure? A gauge? The oil pressure light? No oil returning to the tank?
As you know the oil pump is a gear displacement pump. There is almost nothing that can cause the pump to not develope oil pressure and move that oil as long as those gears are moving.
The only cause for no oil pressure that I can imagine is having the half moon key on the breather pipe either sheared off or missing. That's why this puzzles me.........pg

 

I have seen failure of the pinion shaft bushing in the timing cover cause this problem, you can tell by looking at the motor oil, does it have lots of bronze in it? the fact that you had too much pressure with the wrong housing tells me that the pump is working, I am thinking that your problem is deeper. You may want to remove the thiming cover and take a look and the pinion shaft (crank shaft end) and bushing. if there is too much clearance at this point you will not make much pressure.

 

If you have oil flow (with light pressure) to the top of both rocker box supply lines, this is much more important than a pressure reading on a guage. Most Ironheads don't make readable pressure for a guage.

What is the weight of your engine oil? 60 or 70 is recommended.