Combines M2 hyd cooler

What oil are you useing in the systemIJ I had an M2 gear for 7yrs and never had that problem, changed the oil every other year. Dealer have any comments as to the pittingIJ

Is it rusty where the pipes go through the bottom of the radiator screenIJ Does it have rubber seals in the bottom where the pipes come through. I would wash it out regardless and maybe even put some anti corrosive stuff where the pipes get pitted, but don't cover the whole thing cause you will lose cooling capacity. Another thing you could do is get the oil cooler off of a Hydro and put in there, I think they are made like a radiator rather than aluminium so they will rust instead of pitting. Hope this helps,

The pitting is on the bottom bends of the pipes and where the pipes pass through the rotary screen housing. I put sealer on those places and washed out the trash before winter.I suspect some kind of chemical reaction between the aluminum and the trash to be causing the pitting.I am considering trying something,anything but the factory setup. thanks

You are probably correct about the trash causing some type of chemical reaction. Also when you have two dissemilar metals in contact you set a site up for galvanic corrossion occur. Cleaning the area and protection the area with some type of inhibitor is a good idea. You can also ground the cooler with a cooper wire to some other area of the combine.

Found your problem! I am a pilot, airplanes are aluminum too and cleaning solvents that go through most pressure washers are corrosive to aluminum. Clean the cooler with something like naptha or BrakeClean that is petroleum based but leaves no residue!

Thanks for the info on solvents.Actually, I have only used water to clean it. After reading all these things that could affect the aluminum I wonder why they did not use something more durable on a combine. thanks