High oil pressure

[k hutchins]

Cdahl, mine was leaking from the main gasket. I replaced the "brass" washer on top with a plastic/nylon version from Steiners years ago and no problem. I had the original pot metal cover on it initially, and it developed a small leak. I replaced that with the later model cone shaped one and it turned into a waterfall pouring out. Changed that one out to a different cone type and a newer gasket and no more leak.
I still believe that the high pressure is a contributing factor, so that's my next thing, but l'll probably wait until mowing season is done in about a month.

[Glen]

Hi,
Below is a picture from TM Tractor Parts of where the engine oil pressure relief valve and spring are, to be sure you found it.
They are under the cap on the side of the engine, at the right front. The cap is the shiny part in the pic.
It takes about a 1" socket to turn it.
You might need to remove the upper bolt holding the front end to the engine, to get to the plug.

[phill_mi]

I attempted to post a comment to this thread, but it has not showed up, so at the risk of duplication I will try again. On my 48 FCUB I could not remove the valve, after the spring was removed, even using methods described in the How To on this site. Since for other reasons I decided to rebuild the engine, after removing the governor idler drive gear, I inserted a stiff wire in the oil galley that feeds oil to that gear, and pushed the pressure valve backwards out of its channel. And what I observed was that there was a 'bump' that aligned with the oil galley that is perpendicular to the pressure valve. This brass 'bulge' in the side of the valve caused it to get caught on the perpendicular oil galley and prevented it from moving. I ordered a new valve to resolve the problem.

[k hutchins]

Thanks for that info Phil, lets hope that's not the problem in my case, but it's something to keep in mind.
I'll update after l complete my repairs.

[k hutchins]

Now that mowing season is quickly approaching, l finally made the time to work on these oil issues.
Started with the filter, l found that the gasket was pulled into the housing on one side. Replaced with a new Wix filter and gasket, it also came with the brass washer for the top.
Next l pulled the pan , thank you Dale Finch for the suggestion on the "shallow" socket and universal. I didn't have to split the tractor to get those 3 bolts inside the bell housing. I replaced the gasket and double checked the flange on the pan for flat and uniformity. I had to tap down a couple spots where bolts had been over tightened previously. Reassembled using Loc Tite on the threads so they don't vibrate loose.
Primed the oil pump, filled with new oil, then started it up. Checked the pressure guage still reading high.
Pulled the pressure regulator valve/piston. Thanks to whomever it was that had the suggestion of the 7/16 dowel rod and wedge for removing the piston, it worked like a charm. The piston had a high spot l could feel. Some light filing, 300 grit sanding, and 00 steel wool cleaned it up. I'll post pics after l resize.

[k hutchins]

The dark mark is a high spot

Just a side view, can't really see a bump, but can feel it

All cleaned up, it is a bit pitted, but no high spots

After cleaning up the piston and trying to not take too much material off, l reinstalled with a new spring.
Unfortunately that's as far as l got. I had to destroy the water hose below the pressure valve to get a socket on the cap. I won't be able to start it to check pressure until that's replaced and fresh antifreeze.

I'll update to let y'all know if it all work.
Once again thanks to all who offered advice and guidance

Hutch

[k hutchins]

Hey everyone
I know this is a recurring subject, but l've searched several threads and need more specific direction or information.

My main mowing '48 Cub has perpetually high oil pressure. At start up it pegs all the way to the left on the guage. After it warms up, it with drop to 3/4 when at low idle, but when l throttle up it pegs high again. This is causing oil to seep out around the filter gasket. I thought initially that it was a rear main seal leak and even ordered a new seal from TST, but while prepping to split it l found that the leak is seeping from the filter housing.

The research leads me to the pressure relief valve, but here is my question. When disassembling/removing the valve and spring, (yes l saw the dowel rod technique), is it sufficient to just clean up the valve and tube or do l need to replace the spring? The valve head (for lack of better terminology) is not available from TM, Steiners, or Hamilton Bob's.
Is the valve most likely what's causing my issue or is there possibly another cause l am unaware of?

Any and all information is appreciated, thanks in advance

Hutch

[k hutchins]

Well so much for trying.

Finally got everything back together, new oil and filter, new oil pan gasket, and fresh anti freeze.

Started her up and good news, no leaks any where that l could find. Bad news is, when l checked the pressure guage it's still pegged all the way to the right.

I guess my next move is to buy another guage. I'm leaning toward the one that goes from 0-75. I figure that way at least it will give me an indication of how high the pressure is. With everything l've done, l was hoping that something would have made a difference. At least initially l seemed to have stopped the leaks l had. Time will tell when l mow the first time.

Just for the sake of educating me. What should the pressure be?

[Bill V in Md]

Just for the sake of educating me. What should the pressure be?

Per the Blue Ribbon Service manual for the Engine Lubrication System Gss-1013, the oil pressure at 1600 rpm is 30-35 psi. I believe Jim Becker also confirmed this in his earlier post.

[Dale Finch]

Do you have another 40-range gauge you can swap into it just to see if it's in the "normal" range? Just might be the gauge is reading high, and nothing wrong at all.

[tldec50]

Have you checked your gauge when tractor is not running?Does it return to 0 psi? I have a tractor that the gauge comes to rest at 15 psi when tractor is not running.

[Glen]

Hi,
I think it does happen that the oil gauge pointer goes to the top of the dial when the engine is cold.
I remember seeing one in the past that did. When the engine warmed up, the pointer went down some.
Try running your Cub engine and warm it up well, and see if the pointer goes down some.

But, the oil gauge might not be reading right, like Dale wrote above.

[k hutchins]

Hey everyone

Problem is solved. Replaced the old guage with a new 0-75 guage. Started the tractor and let it run for 15-20 min running the throttle up and back to idle a few times. If my calculations are correct for the new guage, every mark from 0-75 should be 11 psi. If that is the case then l'm running at a normal pressure range between 30 and 35 psi. Obviously the old guage had issues.
Thanks to all who participated and gave advice. Workhorse 2 is up and running and ready for mowing season. I was going to start today, but got a rain reprieve.