Where's the coolant going?

japody · Sep 14, 2017

The coolant in my '69 4000 is going somewhere, but I can't find where. It has a relatively new radiator, water pump, & thermostat. There is no water in the oil, nor oil in the water. Don't see any signs of leaks. I have to put in about a gallon after using it 4 -5 hours, filling it only to a level above the radiator core. I've watched the temperature gauge and haven't seen it get hot until it actually started to overheat yesterday after bush hogging for 5 hours. I'm beginning to think it may be a head gasket. Anyone have any thoughts or ideas what may be causing this or on how to check? Thanks in advance.

FredH · Sep 15, 2017

Maybe do a compression check once engine is warmed up . If you have a truck stop like a T.A. or Petro or better yet , a service place like Speedco , They can do a oil analysis in just a few minutes . Not sure who else may do one that can be done now instead of shipping sample somewere . Although You may not see it in oil and oil / water are not seperating , does not mean it is not there .
That old , no pollution garbage like a EGR cooler , Those are known to get pin hole leaks and lose a gallon of antifreeze a day . Course it usually blows whit smoke when you first start out .

Fred H.

oldnslo · Sep 15, 2017

Our 66 5000 blew the head gasket and it was a very small and slow leak that basically evaporated without leaving a puddle. From memory it was the front cylinder on the left side behind the power steering unit.

Some of the newer antifreeze mixes also don't turn the oil the milky color that it did when I was young so it makes checking for water in oil more difficult.

Egon · Sep 15, 2017

Might be a small leak that opens up as the engine warms allowing cooling liquids into the cylinders from where it goes out the exhaust stack.

Head gasket??

japody · Sep 20, 2017

Took the 4000 over to mechanic yesterday. Waiting to hear how bad it is.

japody · Nov 3, 2017

Yup, cracked head. Somewhere in it's life, someone used form-a-gasket on the head. Not good. Mechanic showed me that there were 5 places where the gasket leaked. Lucky the engine didn't blow! Found another one in a tractor junk yard 92 miles away. I got the tractor back Tuesday and it's running like a champ. I've got a lot of catching up to do.