Mystery fluid

[77 Ford]

I was finishing up some service work on my little 450c this weekend and I noticed a fluid leaking from near the front of the head. Basically behind the bracket that holds the radiator top mount and water pump area.I wiped it off and it smelled like diesel fuel. I got to looking close and noticed I had a hole in the return fuel line near that area. I was pretty much done for the day so I just left it and bought some new rubber hose on the way home.

The next day I noticed the leak was still leaking ( I could dry it and it would appear in a minute or so). I replaced all the rubber return hose and fired up the machine and I was seeing water getting thrown around from the fan. I assumed at this point I had a water leak somewhere and it was not diesel but coolant.

I ran the machine for about an hour just to get the transmission up to temperature so I could go ahead and service it. After an hour of work I noticed everything was dry and there was no water missing.

So now I'm back to I don't know what it was. Is it possible that it could wick diesel out from under the head for 12 hours? I noticed when I pulled the back return line loose it gargled some and diesel came out, I suppose somehow the tank could of been slightly pressurized and forcing it back up and out the hole in the hose?

Anyone ever seen anything like this? At this point I'm going to just watch it very closely I guess.

[Paul Buhler]

I'd look at the water pump shaft seal. If you have the beginnings of a leak, it will show wet when cold and be sprayed by the fan (I think there's a weep hole on the underside of the seal's housing). As the engine heats up, the spray still exists, but drys up on contact to hot items so it isn't noticed. Do you have a fan that pushes or pulls the air? Others may have other thoughts like a loose hose clamp and migrating antifreeze revealing itself by the head. Good luck finding the actual culprit. Paul

[77 Ford]

I'll certainly check that but don't you think I would notice water missing if it were coolant? I recently changed all the hoses and had the radiator repaired because it had fan damage done to it in the past. I would think when that happened the water pump was replaced or rebuilt.

Thanks for the idea, I'm certainly scratching my head.

[Paul Buhler]

I'm certainly scratching my head.

Been there, done that - not much hair left. Paul

[77 Ford]

Update:

After still struggling to figure this out, I removed the radiator. My plan was to really clean the front of the engine and run it with the fan off and see if I could find where my water leak was coming from.

I noticed an odd big flat washer on one of the water pump bolts during clean up. I removed the bolt and of course water came out and it appeared someone had tried to silicone the washer on. My guess is it was leaking out of the bolt and they tried a shortcut fix. Of course I also noticed that the nut was missing from the stud that goes thru the bottom of the water pump.

I'm hoping a full water pump gasket set and a 5 cent nut will cure me up.

[77 Ford]

Update II:

I may have another issue now. When I removed the water pump backing / upper radiator support plate I noticed beside the main water port there was a small 1/8" hole that also bleed out coolant.

When I was cleaning up the water pump parts there is a hole in the gasket for this small hole but no hole in the backing plate. This seems very odd to me, why put a hole in the gasket if it's not suppose to go anywhere.

Any ideas on this?

[KenP]

deleted

[77 Ford]

It's not a weep hole, at least I don't think.

Let me try another way of putting it. From the back of the crawler going forward you have in order:

Head>Gasket>Water pump back plate>Gasket>Water pump

The hole is in the head, in the gasket and then stops. I realize some parts fit many machines but it seems very odd to me to have the hole in the head leading thru the gasket and stop. If the hole where in the WP backing plate it would be dumping off right behind the impeller. Therefor serve no real piratical purpose unless it's designed to drain the head in some way.

If this still does not make sense I'll try and get some pictures. I'm probably making a mountain out of a mole hill but I really need to get this water leak stopped up (ya that's a pun).