oil cooler leak D-4

Not much of a job to fix an oil leak if coming by the connection by the radiator. Just tighten up the fittings or there is a gasket between the oil cooler and the radiator housing that might need a new gasket. Just hope there is not damage to the oil cooler but mine is pretty sturdy and it would take a lot (as it apppears) to damage it.
Not sure what to do with oil in the hydraulics. There is probably condensation in your oil resevoir tank. ( that would be my guess)

thanks for the reply..I will check out the fittings and gasket etc..although I think its the oil cooler itself that might be leaking..as for the water in the hyds..that got in the system over a period of ten years sitting outside with the surge tank cap off...not me!!!..the other guy did it...😊

oil coolers rust out and aren't needed on that tractor. (originally over engineered).

I was wondering about that...and was going look into capping off the lines. My IH 806 tractor has an oil cooler..but it turns over at 2650 rpm and puts out 100 hp..I work it pretty hard sometimes and can see the need for the oil cooler ,at night under a heavy load I have about six or seven inches of red and orange flame coming out the exhuast.....I was out today messing around today with the D-4 pushing some (unfrozen) dirt and didnt ever crack the throttle beyond the halfway point..and operating temp stayed in the yellow..

I have suspected that I am getting diesel in my engine oil..so the other day I changed the oil..left it about 1/2 inch below the full mark..well after running it for a couple hours, it is 1 inch above the full mark..😞 Whats interesting thou is that when I bought this cat the oil level was about the same..so if diesel fuel is getting in my oil..why doesnt the level just keep on rising especially if it is coming from the injection pump???..will do the simple thing first and go after the transfer pump seals and see what happens then..

Fuel transfer pump seals have a tell-tale line draining out between the two seals on every CAT pump I know of. So if you aren't seeing a drip, I suppose fuel could be getting into the oil because the line's stopped up or crimped, but by far more likely culprit is the seal between injection pump housing and engine.

to purge oil from the cylinders, if you can stop the tractor with the blade all the way up on a jack or hoist so you can lower it later, you can take both of the lines on both cylinders loose and then lower the blade to push the remaining oil out of the cylinder. Front of tracks would have to be run up on something so you could get a full stroke lowering it. No reason for there to be leaks with the standard CAT couplings with the o-ring in there, you just need a new o-ring for each one you take loose.

If you haven't already, I would take the cover off the hydraulic unit and clean it manually before refilling. Oil costs too much to waste it trying to get rid of something you can access by removing some bolts.

thanks ccjersey..I did take the front hyd cover off and cleaned it up..I will do as you suggested with the hyd clyinders..I am a little confused about what you said about the fuel transfer seals leaking..is the tell-tale leak visible from outside the pump??or after you have taken the pump out...looking at the parts book, I see the two seals you are talking about on the drive shaft..plus the o-ring on the ferrule and the gasket required. I guess I should do both the transfer pump and injection pump..that way I would cure the problem for sure..save me having to reprime the system twice...

I don't have a D4 book, but on the D311 parts book, I show 3 small drain lines clipped to the fuel filter housing on the front left of the engine. One of these should be a fuel pump tell-tale drain which drains the space between the two transfer pump shaft seals.

the drain lines get plugged with dirt more often than damaged shut. i'd get manuals and study up. good luck.

On the oil cooler, "How much of a job is it to get to it and to fix it?" My D4 7U had the same oil leak but my leak was a gusher. I pulled the oil cooler off and I had to weld up a new bottom housing for the oil cooler as the old one had rusted out. In taking it out, I took out way too many bolts and I messed up the bottom tank gasket to the radiator, and that was even more work to fix, expecially with a number 44 hydraulic pump mounted in the front of the radiator. If I was to do it all over again, I would follow the directions on this website and by-pass the oil cooler with an oil line; or the second choice would be to take the spring out of the oil by-pass valve so you can block off the lines to the oil cooler.