I droved my 55 F350 into the garage the other day, heard a mechanical noise just as I pulled it into the bay, and quickly turned the engine off. When I got out I saw more than usual oil drips coming from the oil pump. Now usually at operating temp the truck will have oil pressure of 80 psi. Last year my distributor froze up and broke gears off of the distributor drive shaft and the cam. Replaced the distributor and camshaft. Before I did that I searched very diligently for the broken pieces and matched those with the broke gears. So when I heard the mechanical noise yesterday I was really really aware and shut everything down. I pulled the oil pump today and didn't see anything wrong; the gears are fine and the drive shaft is fine. So now I'm ready to put it back together and start the truck up again. However, since I have the pump off I thought I would see from you guys how to check the pressure relief valve to see if its sticking (I think I just need to push on it and see that it operates freely) and from other blogs I've read of using a lighter pressure relief valve spring but how does one tell if they have a light one or a heavy one.

Oh, and being older now since I rebuilt the engine and because I can't find anything that guides me, the gears have like a timing mark on them should you can't line them up but should one be to the right or left of the other or does it matter?

I'm running 10/40 oil in the truck if that makes a difference.

 

Ok, I was able to figure out the pressure relief valve - DUH! Now, to go into NAPA and see if I can get a lighter spring and gasket kit.

 

The specification for the spring rate will be in the shop manual. You would need a scale accurate enough and some means of compressing it by the specified amount to check it so it may be difficult to determine what you actually have.

80psi is pretty high at operating temp. Is that cruising or idle? What is it like at or just after startup?

There is a bleed hole on the plug end of the bypass passage. That bleed hole goes to the inlet of the pump make sure that has not become blocked. which would prevent the piston from moving back to bypass the oil. The piston should move effortlessly the whole length of the passage. If there are any tight or rough spots, that could be your problem.

 

.Thanks for the reply, Charlie! I'll check the manual for the spring. I'm running 80psi all of the time. The pressure never goes down from 80. I did check the bleed hole and its clear. But that brought up something; which way does the valve go in? Piston first or the small end. When I took it apart the small end was in the cylinder first. But like I said I'm old and can't remember what I had for breakfast, most days. But I'm trying to remember if I ever took that valve out of the oil pump or even knew it was there in the first place. I'll puzzle over it for a spell, but I'll look into the shop manual and see what I can learn.

Thanks again for the reply, Charlie!

 

You might want to post this to the Y-block forum on here, I think you will get more replies.

 

The small diameter portion of the piston goes in first.