8n Oil Pressure

kjt

New User
I have an 8n that I just recently finished rebuilding. It cranks right up and runs fine. If I pull the line to the pressure gauge off there
is oil flowing. I have a brand new pressure gauge installed, and the gauge reads 0 psi while the tractor is running. Admittedly I did not
do a very good job checking out the oil pump while I had everything torn down. I'm assuming I need to tear back into it and rebuild/replace
the pump, but I just wanted to verify no one else had any ideas before I go there.
 
I would replace the oil pressure gauge first. If you have oil flowing out the line, you have oil pressure. But I would not run it until I tried a different gauge.
 
Echo HCooke. Check with a known good gauge.
I had to prove my hydraulic gauge faulty just a week or so ago.
It led me down quite a rabbit hole until I did.
 
THE one thing an engine needs to run for long is oil pressure. If you really have 0, I'd figure it out before running the engine much.
 
A couple minutes. I knew I had oil flowing, but still didn't want to let it run too long with the gauge reading 0.
 
I just replaced it with a brand new gauge. I thought it was possible the original just wasn't working since I could plainly see I had flow, but the brand new gauge is also reading 0. My thought is the pump is working, just very weak.
 
One thing I didn't think to mention. The first time I started the tractor I did not have oil flow. I read on a different thread how to prime the pump. I followed those instructions and since then the oil has flowed, it's just not building pressure.
 
(quoted from post at 04:24:40 04/19/17) One thing I didn't think to mention. The first time I started the tractor I did not have oil flow. I read on a different thread how to prime the pump. I followed those instructions and since then the oil has flowed, it's just not building pressure.

If it's not showing pressure on two different guages, there are parts of the engine that aren't getting oil. Don't run it until you figure it out.

I bought a new oil pump for a Jube rebuild for about $80. Surely you can get one for an 8N for around there too, or cheaper. It wasn't worth it to me to try to rebuild for that price.
 
I replaced it with the original. Is there any way to test it before buying a new one? I hate buying part to find out I don't need them.
 
I never removed them. However, I also failed to even consider inspecting them while I had it torn down. Is there any way to determine if this is the issue without tearing it back down?
 
(quoted from post at 09:19:54 04/19/17) I never removed them. However, I also failed to even consider inspecting them while I had it torn down. Is there any way to determine if this is the issue without tearing it back down?

Did it run and have oil pressure before you tore it down/rebuilt the first time?
 
It was the pistons themselves. It had been parked for many years and it looked as if the pistons were rusted to the sleeves when I opened it
up.
 
Being that you did not rebuild the oil pump, you might try a straight weight oil. Personally, I prefer straight weight oil in all my tractors, 30wt summer and 20wt winter. I'm sure there will be nay sayers, but I'm too old to change.
 
I wonder what "rebuilt' actually means? Slap some new parts in it & go, or, crank turned, clearances verified, block tanked, passages in block & crank cleaned & verified, all parts carefully inspected, etc., etc............. :?:
 
(quoted from post at 07:48:18 04/20/17) I wonder what "rebuilt' actually means? Slap some new parts in it & go, or, crank turned, clearances verified, block tanked, passages in block & crank cleaned & verified, all parts carefully inspected, etc., etc............. :?:
code:1:2dc995c4bd]

I would say "repaired" not "rebuilt". Sounds like there is something else inside there may be biting him. I would suspect bearings/crank, sure hope it something more simple. [/code:1:2dc995c4bd]
 
(quoted from post at 07:48:18 04/20/17) I wonder what "rebuilt' actually means? Slap some new parts in it & go, or, crank turned, clearances verified, block tanked, passages in block & crank cleaned & verified, all parts carefully inspected, etc., etc............. :?:

I would say "repaired" not "rebuilt". Sounds like there is something else inside there may be biting him. I would suspect bearings/crank, sure hope it something more simple.
 


I realize it has been quite some time, but I got rather irritated by some of the useless posts further down and did not have it in me to respond to anything in an appropriate manner. Something reminded me of this post and since I also don't like reading a forum of someone having a similar issue to what I am, only to find out they never came back and informed what the solution was. You were correct, it was the relief valve. I pulled it back out and re-cleaned the valve, spring and the seat. I'm not entirely sure what it had gotten on it. Put it all back together and I had oil pressure. The tractor ran great and is still running great. Thank you for posing an actual possible solution and not just making useless assumptions.
 
"they never came back and informed what the solution was."

That is definitely disheartening. It can help so many people.
Thanks for posting the follow up; and I'm glad you got it fixed!
 

kjt, "illegitimi noncarborundum!" It may make you feel better to know that some guys here that are the most critical of others have posted a few pics of things at their places. What you can see in the background shows what they are not getting done, LOL.
 

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