OC-46 coolant loss

I have been digging rocks with my newly restored OC-46-3G loader, a couple of hours every Saturday, and I am losing coolant.

It doesn't seem to happen when taking it easy on level ground but while working hard on steep inclines I lose 2 to 3 Litres in a couple of hours and have to shut down when the temp gauge starts to rise above 180.

The oil level and quality are fine - no change in level, no sign of water. There is no sign of any dampness in the exhaust or rough running to indicate water in the cylinders.

The water pump seal dripped a little when I first rebuilt the engine but there is no sign of dampness there after fluid loss and no marks from spray off the fan pulley.

The only place I see coolant is in the belly pan, up under the rad. I pressure-tested the rad during the rebuild and it was fine at 3 PSI.

A friend suggested that I might be getting some blow-by between a cylinder and the water jacket at the head gasket under heavy loads which would build up enough pressure to snort some coolant out under the rad cap when it is nose-down and all
the coolant comes forward to fill the rad to the top. (Nose-down is a common position when working hard!).

Since it isn't real easy to get at the head bolts to check the torque, I'd like to save that for the last resort.

Anybody else got any no-so-obvious ideas about how the coolant might get into the belly pan?

Another question: the book says 140 Ft-Lbs for the head bolts - should that be with the threads dry or greased?

Thanks gang.

(At least on this board I don't have to refer to my crawler as "Brand X"!)

• OC-46-3G

A couple of things to consider 1) if you were sucking coolant into the combustion chamber you would likely notice the exhaust color change to white and would likely see some tell tale moisture as the exhaust stack. 2) Number 1) would not put coolant in the belly pan. Have you checked all the hoses, any pin hole leaks, everything tight in the cooling system, did you check the radiator cap? Are you running a mixture of anti-freeze and water or straight water. If straight water or weak mix are you boiling the water and overflowing the cap? Anyway, my bets would be on the simple things and would check that radiator cap. Last is 3psi a reasonable number...not sure.

Hope this helped and good luck.

Jerri