Possible Coolant "Leak"?

[Gary Lewis]

Guys - I know y'all are tired of my ramblings in Big Blue's Transformation, but I need some creative thinking and I believe I'll get more help in a new thread than buried 288 pages down in that thread.

I've been chasing a coolant leak and this morning I was greeted with another small puddle under the truck. So I modified a radiator cap such that it would keep the air in when I pressurize the overflow fitting. What I did was to remove the little check valve and the seal that fits down into the neck. That means that the air will be held in with the seal at the top of the neck. It works fairly well, but that top seal wasn't designed to hold pressure so it leaks some - which is important to this story.

I put 9 psi to it and suddenly got quite a few drops out of the radiator support. But I've pulled the shroud and radiator loose so I can see the front and back of the radiator and I can't find a leak. And the drops have pretty well stopped.

But then I noticed that the open cell weather stripping I put on the edge of the shroud is wet, as shown below. And it occurred to me that I've spilled coolant as I've been filling the radiator and that foam is right below the neck of the radiator.

QUESTION: Is it possible that the foam is the source of the "leak"? That I'd saturated it with coolant and it has been flowing down and dripping into the core support, which is normally right below it. And then when I put air to the system the leak pushed more coolant out of the foam?

[1986F150Six]

As air is added [9 psi], do the hoses move the radiator such that the foam would be squeezed?

[Gary Lewis]

As air is added [9 psi], do the hoses move the radiator such that the foam would be squeezed?

I didn't notice any movement, but it is possible the bottom moves in the rubber supports. I really wasn't looking at that. The top can't because it is bolted to the core support.

Can't check it out at the moment as I have everything loose.

[Gary Lewis]

I didn't notice any movement, but it is possible the bottom moves in the rubber supports. I really wasn't looking at that. The top can't because it is bolted to the core support.

Can't check it out at the moment as I have everything loose.

Ok, I have Plan B: I think the lower radiator hose was leaking at the radiator and it saturated the foam. The clamp wasn't quite as tight as it could/should have been.

You can see the coolant marks all over the hose in the pic on the left. And the pic on the right shows that the foam above that corner isn't saturated, and there's been some spray - which would happen if the hose was leaking.

Thoughts? What am I missing?

[grumpin]

Ok, I have Plan B: I think the lower radiator hose was leaking at the radiator and it saturated the foam. The clamp wasn't quite as tight as it could/should have been.

You can see the coolant marks all over the hose in the pic on the left. And the pic on the right shows that the foam above that corner isn't saturated, and there's been some spray - which would happen if the hose was leaking.

Thoughts? What am I missing?

I was getting a leak from my bypass hose after replacing the radiator and all hoses and clamps.

I’ve had to check all clamps two or three times now, and will again soon.

Makes me grumble and wonder if we can get good hose clamps anymore. Looked into tension clamps but haven’t found any that I like.

[Gary Lewis]

I was getting a leak from my bypass hose after replacing the radiator and all hoses and clamps.

I’ve had to check all clamps two or three times now, and will again soon.

Makes me grumble and wonder if we can get good hose clamps anymore. Looked into tension clamps but haven’t found any that I like.

Yes, I'm surprised that the lower hose clamps weren't TIGHT. They were when I put the truck together, so I'm not sure why they were tight when I checked before the trip and weren't after the trip.

But it looks like that may have been the source of the dribbles I've been seeing. I think the lower hose/radiator connection leaked just enough to load up the weather stripping and put some in the radiator support. And those two places have been dribbling a little bit as I move the truck around with the lift.

[Gsmblue]

Yes, I'm surprised that the lower hose clamps weren't TIGHT. They were when I put the truck together, so I'm not sure why they were tight when I checked before the trip and weren't after the trip.

But it looks like that may have been the source of the dribbles I've been seeing. I think the lower hose/radiator connection leaked just enough to load up the weather stripping and put some in the radiator support. And those two places have been dribbling a little bit as I move the truck around with the lift.

I always find I have to go back and check hose clamps a few times after changing a hose.

Did the leak stop?

[Gary Lewis]

I always find I have to go back and check hose clamps a few times after changing a hose.

Did the leak stop?

I don't think it is leaking any more. But I've not driven it anywhere long enough to prove that yet. However, I backed it out and let it come up to full temp yesterday, and this morn it has sucked coolant out of the reservoir and filled the radiator nicely. And there aren't any puddles on the floor of the shop. So I think it is tight.

Hopefully we'll take it into AR and MO this fall to see the trees turning and I'll find out for sure then. But all of the clamps are now TIGHT.

[1986F150Six]

I don't think it is leaking any more. But I've not driven it anywhere long enough to prove that yet. However, I backed it out and let it come up to full temp yesterday, and this morn it has sucked coolant out of the reservoir and filled the radiator nicely. And there aren't any puddles on the floor of the shop. So I think it is tight.

Hopefully we'll take it into AR and MO this fall to see the trees turning and I'll find out for sure then. But all of the clamps are now TIGHT.

I have never known anyone who has done major engine work, no matter how meticulous they are, to not have to deal with at least one leak. It amazes me to know that the automotive manufacturers can put out millions of cars without leaks???

[Gary Lewis]

I have never known anyone who has done major engine work, no matter how meticulous they are, to not have to deal with at least one leak. It amazes me to know that the automotive manufacturers can put out millions of cars without leaks???

Yes, it is amazing they don't have problems. They really have gotten their processed down to a science.