Radiator pushing water out overflow

31blackcoupe

31blackcoupe

Senior Member
Working on my 28-29 Roadster. Radiator will not hold water. I've flushed it and filled it below the overflow tube, but it still continues to push water out the overflow tube when running. It's not leaking anywhere else. I'm stumped. Any help would be appreciated. Looks like a stock radiator to me.
Thanks
 
How far "below the overflow tube" did you fill it?

When the engine is cold, I recommend filling the upper tank to only be ~1/2 to 3/4 inch above the bottom of the tank (where the tubes come through -- not the baffle that you see through the filler neck).

Fill it to that level and see if you lose coolant. If you still do, check for leaky head gasket (or cracked block or head).
 
just replaced cylinder head and gasket. engine runs strong just pushes out water. I don't believe the block is cracked. you mention a "baffle". when I had the radiator out something was rattling in the top tank. turned out to be what I would call a "baffle" (4 inch long V shaped brass). I removed it. Does it belong in there? When i fill it i only go well below the overflow.
thanks
 
Jim/GA said:
How far "below the overflow tube" did you fill it?

When the engine is cold, I recommend filling the upper tank to only be ~1/2 to 3/4 inch above the bottom of the tank (where the tubes come through -- not the baffle that you see through the filler neck).

Fill it to that level and see if you lose coolant. If you still do, check for leaky head gasket (or cracked block or head).
Click to expand...

i just replaced the cylinder head and gasket. engine runs strong, i don't believe the block is cracked. you mention a baffle. when i had the radiator ou something was rattling in the top tank. i removed a 4 inch V shaped peice of brass. is this the baffle? does it need to be in there? i fil it well below the overflow to start with
thanks
 
You are most likely not overheating but filling the radiator too full.
Resist the urge to "fill" it back up.
Allow it to push coolant out of the overflow tube and just keep an eye on the coolant level to make sure it stays above the top of the tubes. As long as it covers the tubes you are fine.
It will quit pushing coolant out at some point and stabilize.
Stick a dial meat thermometer directly into the coolant to make sure you are not running too hot.

Also since you have a new head gasket installation keep checking the torque making sure it settles in at 55 lbs.
Check it like every time you drive it until it no longer moves.
Many a head gasket has failed from not keeping at checking the torque until the gasket quits compressing.
 
You only want to cover the tubes. Is your overflow tube been corrected per the service bulletins? You bend it back against the neck. Or you can put a tubing extension on it to get it up where it belongs. That baffle is to spread the water out towards the outsides of the radiator to get maximum performance. You may have problems in hot weather? Try reving the engine with the cap off and see if you can make it overflow with the proper level of water as mentioned. If so, then your radiator is plugged. Some like to restrict flow by trimming the water pump impellers to resolve this issue. IMO that’s a bandied, not a fix.
 
MMM Just went through this with a brand new engine rebuild. 140 miles on it. Out of nowhere water out the overflow tube.................Alternator had loosened up and the fan belt was slipping. Snugged it up and perfecto.
 
As said above, make sure the overflow tube is bent into the right position, then drop a shingle nail into the overflow tube. (Credit to Bill Williams, RIP)
 
31blackcoupe said:
i just replaced the cylinder head and gasket. engine runs strong, i don't believe the block is cracked. you mention a baffle. when i had the radiator ou something was rattling in the top tank. i removed a 4 inch V shaped peice of brass. is this the baffle? does it need to be in there? i fil it well below the overflow to start with
thanks
Click to expand...

Yes, that sounds like the baffle, and yes, it needs to be there.

Ford did not spend any money on any part that was not needed.

Water coming up the hose from the water pump needs to not hit the underside of the radiator cap directly, or else you lose coolant. The baffle redirects it to the sides of the upper tank.

You can try a large-head roofing nail in the overflow tube. That might slow down the coolant escaping. Faster and easier than removing the upper tank to reinstall the baffle.
 
Wow! Thanks for the replies and suggestions guys. Yes, I have been only filling it enough to cover the plates. I like the idea of the roofing nail! The baffle I took out was loose, so I thought it was a broken part of some sort, that's why I removed it. I will also check and bend the overflow tube and the fan belt for tightness. I've been re-torquing the cylinder head to 55 every time I run it. Amazing it gets lose so fast. Hopefully these tips will get me fixed up! Thanks again gentlemen, hope you enjoy your Holidays!
 
Here's a picture of the bent tube.
 

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Check for grease in side the top of the tank with your finger. If it is on there it is in your tubes. I just went thru that with a members coupe. It is from the rear bearing of the water pump. Tried the cascade packets for a season, it was to bad for that to work. Removed the radiator and took to a shop and did a chemical cleaning at a radiator shop. That did not work at all. Then removed it again later that same day as installed and took it to another shop. They baked it in an oven 3 or 4 times and got the grease out that way. We will resume testing again next summer with driving it. The water pump is good and the block is clean.
 
Bob C said:
Here's a picture of the bent tube.
Click to expand...

Note that the tube passes up through a baffle.

To bend the tube on mine, I inserted a Phillips screwdriver into the overflow tube that mostly fills it up, then gently bent up a bit. Pull the screwdriver out a bit and bend up a bit more. Repeat this to get a nice curve in the tube without having it kink.
 
What happens if you don't keep adding coolant? Does the level drop so far that it starts to overheat?
 
Jim/GA said:
Note that the tube passes up through a baffle.

To bend the tube on mine, I inserted a Phillips screwdriver into the overflow tube that mostly fills it up, then gently bent up a bit. Pull the screwdriver out a bit and bend up a bit more. Repeat this to get a nice curve in the tube without having it kink.
Click to expand...

Jim,

That’s a great idea. I was wondering how to avoid creating a kink in the tube when bending it.

David Serrano
 
I don't understand, what difference does bending the tube to the other side provide? It is still at the same height.
 
old31 said:
I don't understand, what difference does bending the tube to the other side provide? It is still at the same height.
Click to expand...


The tube is NOT bent side to side, it is talking about front to rear of radiator.
 
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