pitted fitting M6800

[fcoats]

I have a stuck thermostat on my 2004 M6800 with loader cab & FWA with about 1,700 hours. I removed the thermostat and found pitting on the thermostat housing under the hose. There is no pitting on the interior of the housing. What could cause this, and could there be pitting on the interior of the engine. I'm the second owner and the first did not appear to believe in maintenance.
Thanks,

 

[Tooljunkie]

Coolant. Good for 5 years max.yet when everything had the old green coolant it seemed to me it lasted forever but was good for only 1-2 years.

Electrolysis is another thing that corrodes parts, but fresh coolant has inhibitors. In my shop i stock only one coolant,universal long life. Now its an individual preference for coolant choice,but a couple gallons every 5 years wont break the bank. Done in due time flushing system should not be necessary.

Now as far as the corroded part,if its not too far gone a good epoxy like jb weld to fill the pits and make a good sealing surface may be an option. Replacing housing is of course your best option.

 

[North Idaho Wolfman]

If I'm understanding you right, The pitting on the exterior of the housing under the hose is a result of corrosion between the aluminum and the acid in the rubber hose.
Not a whole lot can be done about this besides a little coat of silicon grease on the fitting before putting the hose on.
I wouldn't worry about the interior of the engine if the interior of the hosing is good.

 

[fcoats]

Thanks for your responses