Low oil pressure in a C

Guys -

My college-type son just was given a C by his grampa. We've played with this tractor for quite a few years, but now it's his to work on. He is now having all sorts of ambitions on what work to do to it.

This tractor has always registered low oil pressure. Hoping it is not to do with the crank and its bearings, I've read several posts in the past where there is an issue with a plate or cover on the oil pump that warps & thus leaks the pressureized oil, giving low pressure readings on the gauge.

Can someone point me in the direction I need to inspect and verify this potential issue ?

Thanx !

I don"t have a C, I have a Super-A, but on my oil pump, part of the gasket between the pump and it"s cover was blown out.
I can"t tell you if that was the sole source of low pressure for me, because I overhauled the engine at the same time, but it couldn"t have helped.
Hopefully your C is the same: my oil pump removal was as easy as dropping the pan, and removing two bolts on the right side of the engine, and the oil pump (with a little wriggling) dropped right out.
Mine has a "floating" sump with a screen, and it"s worth making sure your screen isn"t gummed-up with sludge, which would also reduce flow. It"s an easy start to tracking down the problem!

My super c has always had what I consider low oil pressure, It did 20 years ago, and still does after engine overhaul. Most of the experts agree that all you need is 10 pounds of pressure per every 1000 rpms. If you have that I would not worry about it.

also, when you drop the oil pump cover, look for wear marks from the pump gears. real common problem. my b was worn and also the super m i am currently rebuilding. you can take some emery cloth on a sheet of glass, and using a figure 8 pattern, sand the surface back smooth

We have two Petes in on this one so this might get confusing . . . ;8^)

The Pump setup on P&R Pete's Super A is the same as the C.

So, Pete up in MI, it's fairly easy to get to and check out. Drop the oil pan. There will be four bolts that are longer than the others, so keep track of where they go. You will see the pick-up of the oil pump sticking out the bottom, sort of a flying saucer shape on the right side a little aft of the middle.

The whole pump assembly is easy to remove. Not far up on the right outside of the motor, if you follow up from the pump pick-up, you'll see two bolts maybe a couple of inches apart, that should have a flat piece of soft metal between them and the block, with the corners of the soft piece bent over to keep the bolt heads from working loose. Flatten that soft piece out remove the bolts. They are all that hold the pump. Though I've never had one just drop out, it's not a bad idea to keep one hand on the pump from underneath when you pull the second bolt. From there, it's a matter of pulling straight down, as all that's left to engage the motor is the drive gear at the top with meshes with the cam. Sometimes it helps to jiggle the cam by moving the engine fan back and forth a little(ignition OFF!!!) to free it up.

From there, you can start just like P&R Pete suggested by using kerosene or an aerosol, like brake cleaner, to clean up any sludge. (You will, of course, be cleaning any sludge out of the oil pan while you're in there, and the depth/quantity of that will give you some idea whether that's impeding the uptake of the pump.) If that's all squared away you can evaluate what you have, and go on to replacing the gasket and sanding the cover back smooth and flat if needed.

Only other suggestions are to have replacement gaskets on hand for the pan (NAPA has them) and for the cover on the oil pump if you open it up (there may be other sources but likely a CaseIH dealer part). That and, if you get into sanding down the cover, get a new 8x10 piece of window glass from the hardware -- just don't use an old pane you may have laying around that is so old that it has ripples in it.

Good luck and let us know how you make out!

Have you tried swapping out the oil pressure guage? I've had a couple that had a bad guage that registered low oil pressure, then swapped the guage out with one that I knew was correct. Turned out to be nothing more than a bad guage.

I bought a B that lived on a farm we farmed for nearly 20 years when I was 14 and Dad and I restored it from ground up.Every nut,bolt,and washer,but never run over 15 lbs oil pressure,and it was same at idle as wide open,and guage went to 0 when you killed it.Ive got a strong running VAC Case the same way

I bought a B that lived on a farm we farmed for nearly 20 years when I was 14 and Dad and I restored it from ground up.Every nut,bolt,and washer,but never run over 15 lbs oil pressure,and it was same at idle as wide open,and guage went to 0 when you killed it.Ive got a strong running VAC Case the same way

Just finished up fixing an H with that same problem. That tractor had never had great oil pressure in the 12 years I've owned it, but it finally got to the point that it had the same as NONE when warmed up, and that was even with the throttle wide open. I flattened out that oil pump bottom cover using a good sized honing stone. The H will now peg the guage when first started, and after running for better than 30 minutes, still registers about 3/4 up on the guage at idle. This is on an engine that is basically just flat worn out and desperately needs a total rebuild, but now she should be good for another winter of pushing snow.

My 404 had low oil pressure when I got it. It had the warped oil pump cover that everyone else has mentioned and part of the cover gasket was blown out.

Sanding the cover flat on a piece of glass with sandpaper taped to it removed the warp and the wear in the cover from the gears riding against it. Putting it back together with a new gasket fixed the problem and it has plenty of oil pressure now.

Funny thing is, it looked like it had been done before but poorly...

Scotty, excellent reply, as always!

I"ll add, from my own experience, that I had two paper-thin gaskets (which I procured in my engine rebuild kit), and there have been some on this forum who have gone to some considerable effort to measure gear clearance when buttoning the bottom of the pump back on, something Pete in Mi. will have to figure out, so Scotty if you wouldn"t mind making a mention in this regard...

(In my instance, after I had a machinist mill my cover flat again, using one gasket resulted in the gears slightly binding, and with two gaskets it spun freely, so I went to no more effort to measure, and just used two. Maybe not the best way to go about it...)

The "gauge" issue may be a good point. My gauge maxes to 30#, had been reading 10# until the overhaul, and now stays absolutely pegged on 30# at anything above an idle. If I"m not mistaken, an original gauge went to 60#. Knowing what is correct may be helpful to the other Pete also.

Lastly, as Scotty did a hugely better job than me in "assuming nothing", I"ll mention, in case Pete finds this confusing, as I first did, that you have to take a cast-iron cover off the bottom front of the bell housing to get at the rear of the oil pan.

So that's where those other gaskets go! LOL I must have five or six of them running around. (Truthfully I'll have to go look -- I have remnants of two or three sets out there that I have to scavenge around in for something now and then. Last time I think it was for the mag/distributor mount.)

I wish I could have offered more about the goal in flattening out the pick-up cover, but I haven't actually had to do it. Just lucky, I guess. For Pete in MI, my understanding of the aim of that whole operation is to have a good seal and to have the clearance between the ends of the gears and the cover within spec. which is .0035 to .006 inches. I'm not sure how one would check that with anything other than plastigauge. Others who know more about it may jump in to confirm or correct that, or with a better way. But to P&R Pete's point, between worn components and then having some slight amount of material honed off in leveling the face of the cover, the gaskets do double-duty as shims to help set that clearance. So it's important to have the correct (not the Correct Police correct, but the mechanically correct) gaskets on hand to make that clearance right.

And the best idea of the day is the gauge. Some IH gauges of that era came marked for actual pressure, usually topping out at 45 or 75 pounds, depending on the tractor. Others, like the one original to the C, came with a dial showing simply a red zone and an operating range. A good first step, before dismantling anything would be to get to an auto parts and for $15 or so, pick up a Stewart Warner or other make gauge with some calibrations on it to swap in in place of the IH gauge. I've got one physically comparable to the one on the C (simple housing with the garden variety 1/8" NPT fitting on the back) and graduated by tens from 20 up to 80 psi. I've used it on all sort of things to get a better idea of what actual pressure is (though it's by no means certified to be accurate) and as a comparison for a suspect gauge. Quite handy, it lives in a zip-loc bag in the same drawer as my compression gauges.

The book calls for 50-60 psi with the motor at full tilt (1400-1540 rpm) but, honestly, I've never seen it on anything but a good tight motor with a fresh-ground crank. 40 would probably be a more typical high, 20-25 would indicate some wear that will eventuallyhneed attention if the tractor is a worker, but is not cause for alarm.

Another two cents. I'm out almost a nickel today!

Thanks for the great insight.

Is this cover a flat plate or die formed? Is the root of the problem that the plate is too thin? Wondering if it would be advantagous to build a new plate of heavier steel? Sounds like clearance to the gears is also a critical thing to watch.

This'll give us some good ammo, along with a compression test, to see where to go regarding any form of a rebuild.

Thanks all !

Pete

Here you go...

You are the man, Pete. You have more pictures of more things in the guts of a tractor than anybody I know. I wouldn't want to be the one to have to clean up the outside of your camera after a photo sesion, but I can sure appreciate how helpful the photos have been.