The Stovebolt Site Forums The Shop Area General Truck Talk antifreeze leaking after freezing weather

I checked my antifreeze and it was good down to -25 degrees. Today after work I noticed antifreeze under my truck('53 GMC)at the front of the motor. I pulled it inside the garage and it was leaking out of the hoses where they connect to the radiator. Also leaking out of the upper hose pipe at the connection to the radiator. It had never leaked before but it got down to 4 degrees today. Any suggestions as to why this would happen? Thank you

antifreeze is slippery stuff, might try re-tightening the clamps when the engine is hot, surprising what an eighth turn will do - also make sure the rad isn't overfilled and developing too much pressure and that the rad fittings haven't been dinged at all, and if necessary, a light wipe of #2 Permatex does wonders

Bill

Well, I'm just guessing here. But, if it didn't leak before the cold weather it is a matter of shrinkage and flexibility. The metal in the radiator is going to shrink ever so slightly the colder it gets. Also, the rubber in the hoses gets less compliant the colder it gets (see Challenger disaster). Combine the two, and you might not get proper sealing. Tighten those clamps and see what happens. Unless your radiator or block has cracked and is leaking from there, then your antifreeze is doing its job.

In other words....the antifreeze shouldn't be right up to full, unless you have an overflow connected to the rad. Dutchy

I run into this all the time at work on our fleet of school buses. The hoses do not change in size at the same rate metal does when it gets cold. To cure it for good, replace the screw clamps with spring clamps. The spring clamps apply the same amount of clamping force no matter what the temp is out side, screw clamps stay at the same size even if the hose doesn't.

Tightening the screw clamps will also work, just tighten them while they are cold or till the leak stops.

Joe

Thanks for that information and advice, Joe

Thank you, I am going to replace the clamps

jdzcnO,

Likely not the situation you're dealing with, but if it's not the hoses or hose clamps, you might have the same thing that gave me fits for months; My original 57 radiator had a bunch of pinholes in the brass just below the upper hose pipe. Probably from age, corrosion, flex, etc. I could not find the pinholes but kept seeing the fluid all over the upper fins after a run, particularly when I overfilled the radiator. Tighten as I might, I still kept seeing the leaks.

When I wire-brushed the paint and corrosion off, I could clearly see the antifreeze weeping out of the pinholes.

Like I said, may not be you issue, but I chased that tail for too long not to throw it out there. I ended up using Muggyweld to seal the pinholes until I can afford a recore.

Best,

Jim

I you don't have an overflow tank, as long as you don't keep filling it, it will find it's own level. Many people keep topping them up then complain that they're overflowing...

It was 11 degrees all day today and the 40 new buses we got in last month were all leaking coolant. Hose clamps were marginally tight from the factory down south where it was warm, in the cold, they leak. I spent two hours outside under buses tightening hose clamps today!

Joe

Yowza!!! And I [censored] about my shop being too hot I don't envy you...that would have gotten old real quick.

When I used to drive trucks, we would have the same problem like Joe said. Our Volvos were notorious for leaking antifreeze from the lower hose to radiator connection when it was cold out.

It is possible to tighten standard hose clamps too much. They pinch the hose and don't apply even pressure. I like dual wire hose clamps. they seem to do a much better job.


http://www.emwardfastenings.com/double-wire-clamps.html

JoeH, Great tip re. the spring type hose clamps. Who'd a thunk it.
Jim

Seen the the same thing many times when it gets real cold.

Could be the heater core and leaks most when you are using the heater in cold weather. It needs to be addressed wherever the leak is coming from, it will not get better on its own. If you cannot locate the leak location and complete a fix I recommend that you take it to a trusted mechanic…

I always considered the simple spring type hose clamps cheap and cheesy, and have no place in an automobile. Now we know why they used them! A royal PITA to remove/install without the proper hose clamp pliers. That is probably why they got pitched when the hoses got replaced. I had planned on using them on a 216 in my 49 just to be correct. Now after reading about why they use them, I will install them without a second thought. Where can you find the special pliers to remove/install them?

I once took a regular pliers and filed a groove in each jaw. Not as good as a factory made pliers but it got the job done.