Ford 3000 Blown Head Gasket?

blehmann · Jun 20, 2016

My 1966 Ford 3000 gasser has spit out coolant ever since I bought it three or four years ago. Not a lot, but not a little either. Probably a gallon every six hours of run time. I changed the radiator cap and washed the radiator coils this past Saturday. On Sunday I started it and moved it maybe a hundred feet and shut it off. A couple of minutes later I looked over and saw a puddle of coolant on the ground. This was the first time that I realized that the thing was spitting immediately. My first thought was that there has to be compression getting into the coolant system because the overflow sure wasn't caused by overheating. I read a bit about it and one of the signs of a blown head gasket is bubbling in the coolant. I pulled off the radiator cap and started the tractor. There is enough bubbling to turn the coolant to foam. I went ahead and ordered all of the necessary gaskets today.

What still puzzles me is that the tractor runs great and there is no white smoke or an oil level that climbs up the dipstick. I reasoned that it must be a one way leak that is being relieved by the radiator cap. I went ahead and shredded some weeds this evening for about an hour and the thing ran just like it always runs.
Is there anyone out there that is familiar enough with the head and block to explain to me where this pressure could be leaking across. I am just curious now and want to know what to look for when I pull the head this weekend.

Raspy · Jun 20, 2016

That sounds like it might be a cracked head instead of a head gasket. With all of its run time and good performance since it's been leaking, it seems like it must be something else. Also, if it is a head gasket I would not start it again as it might hydraulic.

Were you able to see where it was coming from when you saw coolant on the ground? Like the radiator overflow, or from the block?

blehmann · Jun 21, 2016

The coolant is coming out of the overflow tube. That is why it never occurred to me that the problem was anything other than a slight overheating problem. I certainly hope that it isn't a cracked head as I don't have a clue on where to start looking for a replacement. Thanks for bringing that up. I will have the head checked prior to reinstallation.

RickB · Jun 21, 2016

Are you filling the radiator brim-full? If so, you are creating your own problem. The system has no recovery tank, so it is necessary to leave head space in the top tank for coolant expansion. Fill to about halfway between the top of the tubes and bottom of filler neck. No more.

blehmann · Jun 21, 2016

RickB said:
Are you filling the radiator brim-full? If so, you are creating your own problem. The system has no recovery tank, so it is necessary to leave head space in the top tank for coolant expansion. Fill to about halfway between the top of the tubes and bottom of filler neck. No more.

The coolant is down about three inches. On cold start it immediately foams with bubbles and expands to the top of the radiator. This is not a heat expansion problem, there is air,gas, exhaust, ???, getting into the cooling system. Just trying to think of all the options and where to look when I tear it down.

RickB · Jun 22, 2016

blehmann said:
The coolant is down about three inches. On cold start it immediately foams with bubbles and expands to the top of the radiator. This is not a heat expansion problem, there is air,gas, exhaust, ???, getting into the cooling system. Just trying to think of all the options and where to look when I tear it down.

OK. I was thinking of options BEFORE you tear it down. You'd be surprised how often folks keep filling radiators brim full.