Ford 8N high oil pressure

   / Ford 8N high oil pressure
  • Thread Starter
#21  
Yes, with the plunger out it should dump the oil out the bypass passage, just be clear remove the spring and plunger but put the cap back on. Don't worry if the engine has zero pressure for a few minutes at idle, the N engines can and have run on as little as 5 lbs. at full load for years.

If the pressure does not drop then it is a blockage in the bypass passage, I don't really think this is the problem but it might help point toward something else.
Pulled that spring and plunger out, put cap back, pressure dropped to almost zero ran it for a few, put the plunger spring assembly back in pressure back pegged again. Feel pretty safe just calling it a bad relief valve/spring assembly. Hopefully they'll send it in soon. I don't wanna run it with high pressure or no pressure. I'm gonna lose out on my fain free week unfortunately. That's how she goes tho.
 
   / Ford 8N high oil pressure
  • Thread Starter
#23  
Well well bet yall thought this was over and done with. Wrong. Got the new parts in today and this evening I swapped them out. Oil pressure is still pegged out at 50. The new spring was significantly stiffer than the old one. Is there some step to this I'm missing? No plunger and spring there is near 0 oil pressure, new plunger and spring installed there is high oil pressure. I feel like I've missed some simple step in this process.
 
   / Ford 8N high oil pressure #24  
The only thing I would suggest now is to try another gauge that goes to a higher pressure so you can see how high it actually is. The steps after that is to drop the pan to see what is/has happened to the pump itself to make that much pressure OR slowly remove coils from the old punger spring you have until get the pressure you want.

Usually on the 'N' series the problem with oil pressure is being low which is not really a problem. Personally if it were mine I would first find how what the pressure actually is then as long as there are no leaks ( filter is the only place they would show up ) I would work it for some time to get it well up to operating temps to see what the pressure does.

Do you know what weight oil was in it before you changed it? It might just be you have a good tight engine and the 40 weight is just giving you the much higher cold pressures. Just spit balling cause as I said most times it is low or no pressure with these old tractors which most of the time is related to a cracked pickup tube on the pump.
 
   / Ford 8N high oil pressure #25  
This is pretty baffling - the first I've seen of too much pressure on an N tractor. Also spitballing here - was any work done on the oil pump recently?
 
   / Ford 8N high oil pressure
  • Thread Starter
#26  
This is pretty baffling - the first I've seen of too much pressure on an N tractor. Also spitballing here - was any work done on the oil pump recently?
Not that I'm aware of. I will say, I did run it a good while yesterday and I found at a medium throttle after thirty minutes of running I was finding the pressure dropping back down to high 30s. I think I'm just gonna have to be okay with it unless I start hearing engine noises or leaks.
 
   / Ford 8N high oil pressure #27  
Not that I'm aware of. I will say, I did run it a good while yesterday and I found at a medium throttle after thirty minutes of running I was finding the pressure dropping back down to high 30s. I think I'm just gonna have to be okay with it unless I start hearing engine noises or leaks.
Well, if your new pressure relief valve is working correctly, it should open at around 50psi so you should be ok. If you don't mind wasting the new oil, you could drain and refill with 10w-30 and see if that works better. Usually, N owners are going higher because they have the opposite issue. Good luck with it!
 
   / Ford 8N high oil pressure
  • Thread Starter
#28  
Thanks to everyone who pitched in on this with me! Y'all have really helped and even thought I'm not 100% sure the issue is solved I don't feel pretty good about motoring on. This planting ain't gonna do itself.
 
 
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