Calling all Hercules IXB experts.

[T.R.K.]

The Hercules engine is in a Minneapolis Moline BG.

Please don't tell me to ask on the MM forum. All I get from them is Its not a 'real' Minneapolis-Moline.

I am having an oil pressure problem. I rebuilt the engine last winter. reground crank, new main , cam and rod bearings. new sleeves, pistons, even new valve seats and guides.
Ok. The problem. When cold it pegs the 80 psi gauge. (Tractor Supply or Napa gauge, by the way.) But when it warms up, the oil pressure drops to near zero at idle. Less than 10. Maybe 5 psi.

I have already installed a shim in the relief valve, and cranked it down about as far as I think I can and it did help some. Before that the gauge would fall all the way to zero.

A couple thoughts: I should have miked the crank or checked the bearing clearance before assembling it. (I may have done this, but almost a year later, I really don't recall.)

I wonder if the machine shop removed any plugs from the oil gallery and I missed them.

I also wonder if there is supposed to be a restriction in the oil line to the governor assembly, the oil line runs external around the block to the governor. I replaced all the external tubing when I rebuilt it.

I wonder the same about the oil filter. Is there supposed to be some restriction in the oil line to the canister. It is mounted beside the air filter.

I also wonder if I just plain have a worn out oil pump.

Any thoughts appreciated.

Thanks!
T.R.K.

 

[moresmoke]

Dont have much experience with one other than owning one that works just fine. I would suggest giving Landis Zimmerman a call. The same engine was used in the Cletrac/Oliver HG/OC3/GG. That tractor was originally designed as the Cletrac GG.

 

[Steve@Advance]

Just general information on oil systems, but the reason you get such high cold pressure is from shimming the relief spring. Shimming the spring only increases the high speed pressure, and has no effect on idle pressure. I would return that to the original position before something breaks or blows!

You may be onto something with the governor oiling. There may have been a restrictor in the old line or a fitting that got replaced. If the governor is free flowing oil through it, that would be a good place to start.

Same with the oil filter. I suspect that uses a 'bypass' filter where a small amount of oil is passed through the filter and dumps back to the crankcase. If it is, it will either have a small restriction in the line leading to the filter, in the filter housing, or inside the filter itself if it is a spin on.

An easy test would be to disconnect and plug the oil filter (only if it is a bypass filter) and the governor feed, one at a time, and do a test run to see if there is an improvement.

 

[caterpillar guy]

Lots to go back and check now. Oil clearance in bearings both rods and mains. Not hard to do withpan off. then the oil clearance in the cam bearings. IF old bearings and they ground the cam did you get the bearings from the machine shop or get them yourself? the oil clearance in cam bearings is the first to leak off oil pressure. Pull the tappet cover and look for oil coming up through the valve train while idling and warm. If you have that most likely your gage is not good new or not. This will also help tell about the oil pump if no oil at the vale train then weak pump or excessive oil clearance problem somewhere. And then what oil are you using and what temperature are you running outside now. If southern warm temperatures with 10 weight oil there is probably your problem. If northern cold temperatures and heavy oil it could be starving for oil till it warms up the oil. By then the engine is worn enough to loose oil out the bearings faster then even a new pump can fill it. Then there is your oil pump is it new or just the old one with no checking of fitness for internal parts on it. Easiest thing is to change the oil gage and see if there is a difference first then dig deeper if that is not it. Maybe even use the old gage to check with.

 

[560Dennis]

Verify the gage is in calibration , correct .defective.
If you didnt verify the oil pump at rebuild do that also . Verify the the relief spring is not broken or weak !
Mistakes happen start over with check list .
BUy the IXB motor manual .
What Im thinking , if dont measure your just guessing , what the old timer say.

 

[MARK ROBKE]

I am unfamiliar with this engine, but, could have an oil thermostat and an oil cooler? Also, what rpm is the engine idling at? We had 340u IH tractor that had ZERO oil pressure at idle when hot. When we had to let it idle hot, we just raised the RPM a little-maybe 1000RPM. I was a kid back then and we ran it that way for years. When I grew up and became a mechanic, I told Dad I was going shim the relief in the oil pump. It raised the idle oil pressure, and the high idle pressure also, but it did not exceed 60 psi. Mark.