Ford 641 been sitting over 1 year, No Oil Pressure

RTR

Well-known Member
Well guys....I finally got the 641 back up and running after almost 2 years. Nothing was wrong with it but a dirty gas tank, so I decided to tear down and do a cosmetic restore. It has been a backburner project, and now I got everything all put back together and started her up for the first time in about 1 year, 6 months.

Problem is....there is no oil pressure registering from new gauge.

She cranks and runs just fine, like always. I thought there might be air in the tube coming from engine to gauge so I loosened it from the gauge and started the tractor. Let it run for a minute or so, and nothing. Scared to run it anymore than I have.
 
I think I might disconnect the oil gauge fitting on side of block & see if oil comes out, because if it were not oiling at all, I think it might be talking to you after the run time of that video.
 
Yeah, I've run it more than just that video too. How in the heck do you get to that end of the tube?? It's tucked back in there behind that thing that looks like a starter. I don't think I could get a wrench on it.

Would it matter if I put a bend in the line like this so it would fit under the dash better? Would that loop cause it to not have oil come out the line?
13373.jpg
 
Loop not a problem unless it is too tight and becomes a kink.
Line and gauge need to be air tight to get good oil pressure reading.
i second the suggestion to see if oil is actually flowing.
if there was zero oil pressure the motor would get hot real quick and the valve train would be noisy.
If you open the oil filler, is oil splashing around when it runs?
 
I'm pretty sure that's a solid lifter cam, so the valves would not get noisy with no oil pressure. I agree though that if it did in fact have no pressure, he would have already found that out the hard way.
 
So what is the best way to fix this? I don't want to run it anymore until I know I have pressure. Should I just try to unhook the pressure gauge line from the block? How do you guys get to it? Another question.... Is there no way to prime the oil pump ??
 
(quoted from post at 01:49:16 12/30/12) Yeah, I've run it more than just that video too. How in the heck do you get to that end of the tube?? It's tucked back in there behind that thing that looks like a starter. I don't think I could get a wrench on it.

Would it matter if I put a bend in the line like this so it would fit under the dash better? Would that loop cause it to not have oil come out the line?
13373.jpg
s has been said, unless a tight kink, the loop is not a problem. Yes, it is a tight fit behind the hydraulic pump. Most likely have to remove the pump to gain access (bolts to engine and to hyd manifold on bottom with o-rings at joint).
 
Just a thought here. If you remove the distributor, You can chuck up about 15" of 1/4" hex rod in your drill and run the pump. This way you can check for oil pressure without running the engine.

I think I would remove the oil pressure gauge tube from the elbow that goes into the block behind the hydraulic pump. Then run the pump as above and see if you get oil flow.

Any help?
 
Air in the line would make no difference. The motor will run quite a while with the prelube on the bearings before you hear noise.

I would unhook the line where it comes off the engine, no or low flow then no pressure.
 

I wonder what the problem is? It had great pressure before. Think it's just a problem with the line going to the gauge ?
 
I'm thinking that oil line is the problem. It could be kinked or plugged. I wish it was easier to remove that line from elbow going into the block. Not one of Ford's better ideas.
 
(quoted from post at 21:11:48 12/30/12) I'm thinking that oil line is the problem. It could be kinked or plugged. I wish it was easier to remove that line from elbow going into the block. Not one of Ford's better ideas.

I'm afraid to remove the Hydraulic pump as I might cause more harm than good. Would it hurt the gaskets or 0-rings to remove it and reinstall it. ?
 
(quoted from post at 14:35:54 12/30/12)
(quoted from post at 21:11:48 12/30/12) I'm thinking that oil line is the problem. It could be kinked or plugged. I wish it was easier to remove that line from elbow going into the block. Not one of Ford's better ideas.

I'm afraid to remove the Hydraulic pump as I might cause more harm than good. Would it hurt the gaskets or 0-rings to remove it and reinstall it. ?
ometimes it all works out, sometimes you tear a gasket???
 
The O-rings between the pump and manifold are probably reusable. But as JMOR said, the gasket is a maybe. At least it is cheap. Don't try to make one yourself, the thickness is critical. It determines the gear spacing.

You could give the pump a try. Worst case is a minor engine oil leak at the gasket. Maybe an O-rings leak. Small $$$ involved if they do leak.
 
Leaky oil pick up tube to pump inlet or stuck open pressure relief valve woulfd be my guess.
Air in line to oil pressure gauge is definetley not the problem!
 
(quoted from post at 01:50:48 12/31/12) Leaky oil pick up tube to pump inlet or stuck open pressure relief valve woulfd be my guess.
Air in line to oil pressure gauge is definetley not the problem!

Ok well how would that be fixed or diagnosed ??
 
Royse, had commented on a previous post of mine, that I should prime my oil pump. Maybe that is what I should do FIRST. How would I go about doing that. I am used to working on Farmall Cubs, and know that is the FIRST thing you do after they've been sitting.
 
Pull the pan and check the supply tube to the pbunp for cracks or leaky seals. Look at the relief valve in the oil pump and see if the spring is weak or the piston is stuck in it"s bore.
 

Ok. I will have to just suck it up and give it a go I reckon. I have never had to even look at an oil pump before, so I have NO CLUE what I'm doing in that area.

I just changed the oil and filter in the tractor, so maybe I'll be able to save it. Would it matter if I didn't fill the filter with oil before putting it on the tractor? Since it mounts sideways, I figured it would all run out and down the side of the new paint, so I didn't think I should pour oil in the filter. If that is the problem....then that should be an easy fix.

WHAT DO YOU ALL THINK?
 
Now I have never had a 641 or even had the pan off any tractors. (Numerous cars, yes)

Idea that maybe good, maybe not.
If we assume its a un-primed oil pump
or bad leaking oil pickup tube.
What if you overfilled the oil to the point
the entire pickup tube was covered.
Run it,
If still no pressure, you can go ahead and drop pan and "do what you got to do."

BUT on the small chance you do get oil pressure,
drain it back down to normal level.
Run it, if oil pressure drops back to zero,
drop pan.
IF by a even smaller chance oil pressure holds,
my "guess would be a worn oil pump that would not prime itself".

That is what I would try.

What do the more experienced members think?

Pete
 
(quoted from post at 01:35:27 12/31/12)
Ok. I will have to just suck it up and give it a go I reckon. I have never had to even look at an oil pump before, so I have NO CLUE what I'm doing in that area.

I just changed the oil and filter in the tractor, so maybe I'll be able to save it. Would it matter if I didn't fill the filter with oil before putting it on the tractor? Since it mounts sideways, I figured it would all run out and down the side of the new paint, so I didn't think I should pour oil in the filter. If that is the problem....then that should be an easy fix.

WHAT DO YOU ALL THINK?
roblem is Not likely a result of your not filling the oil filter. However, you could perhaps get oil to the oil pump by using a turkey baster to insert oil into the pump's output via the inlet to the oil filter. You can see how this could be accomplished by looking at attached pictures.
Since the oil fitting from block to gauge is so difficult to access, there is another oil output point that you could examine by removing the distributor & turning the oil pump shaft by hand or with a drill. With disrt removed, there is an oil passage in the side wall of the distr hole whose purpose is to oil distr shaft/gear & without distr installed oil will gush out this hole when you spin the oil pump. You can see the path in attachments.
oil_paths_NAA_mkd.jpg

naa_oil_lines_zps54b6890b.jpg

NAA_filter_inlet-1_zpsfe1200a7.jpg
 


My experience, for what it is worth, is that the oil gauge line is removable with the right sized open end wrench; you can prime the pump with your drill and 14 inch bar/rod stock as Kurtnepa suggested; You can make your own hex end onto a square bar on a grinding wheel if you can't find hex; you should not plan to reuse the O-rings on the manifold, in fact you should go to CNH to get the exact right ones. If you try running the pump with your drill, the camshaft allows oil up to the rockers only when in the right position in the rotation so you will need to turn the motor a little by bumping the starter or with wrench on the front nut.
 
(quoted from post at 12:19:20 01/05/13) Sooo, what was it?

We all want to know!

Pete
ust a guess, but since we are into 2013 now, it probably means that the tractor is beginning another year without oil pressure. :twisted:
 

With the cold weather lately (yes I know 25-35 degrees isn't that cold), I've decided to take the time to do some inside work where it's warmer. The tractor is in a building with no insulation nor doors, so it's cold working on it. When it warms up a little bit more, I'll go and get started on it.

THanks for checking up on my guys!!!
 

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