The Stovebolt Site Forums The Shop Area Engine Shop 42 216 cooling problems.

Okay, I couldn't find a recore for under $400 so I bought a new rad that would fit in the truck dimensionly. The truck runs fine until I put a load on it, then the engine says 180-190 but the rad is boiling over. I tried open cap and sealed cap. I'm assuming the rad is too small but want other opinions.
It doesn't feel like the stock 4 blade fan pulls very much air at all, is there a better fan that will fit?
Also, I have the heater hoses just blocked off, do they need to loop?

Check your lower rad hose first. It should have a metal spring in it. They close up under load if the spring is missing.

Running a 4lb rad cap? Or sometimes you can find 7lb ones in stores. Try it with cap off or laying on loose and see if it boils. Where did you get a rad that skinny? Sure it's not for a "Pinto" or something small??? :p Don't new rads go for around $299 in vendors catalogs? I was looking last year for my 54 2-ton and was cheaper to buy than recore at time. Did you flush out block? Why did you need new rad? Mine was overheating even after flush, but rad was clogged at bottom and I had to have it pressure backflushed at old shop I use here. Puked out all kinds of rusty gunk that didn't even show up in anti-freeze when running. It's OK now. Course, you have new rad now, so doesn't apply. So....Never Mind!

Maybe it's not the cooling system. Check how much spark advance you are getting. Should be around 25 deg.

There were some aftermarket 5 blade fans available in the 60's, but I haven't seen any since. For more fan you just about have to either go with the flex fan or add on an electric. But, if the engine runs hot at speed, more fan won't help a bit. On your heater hose, mine has a shut off valve for the summer, so blocking them off should be okay. However, I was always told to loop the hose because that's your bypass when your thermostat is closed.

Is your radiator a 3 row or 4 row? And what was your old one? I don't know enough about the wartime trucks. If you went from a 4 row to 3, you won't get as much cooling. I understand about some areas where the radiator shops are unreasonable. Fort Worth was like that, cost about twice as much as here in Wichita. Another check is to open the drain on the side of the block. If coolant doesn't come out or is very slow, take some wire and start cleaning. Then flush the block. It might help.

Well the stock rad just started leaking to bad and no one could fix it.
I just went thru the picture book till I found one that would fit, no idea what it is for. It's just a 3 row, but I thought the new designs were more efficient.
I ran the cap loose, it only overheats when pulling a load. I think I found a correct rad so I'm hoping it works out.
It was kinda wierd when it would erupt while refilling it did look like rust in the water. Maybe I will flush the block and see what happens.
So I can take a flex fan and make it fit?

First pull the water pump and make sure the impeller isn't rusted up or out and that the block jacket isn't full of crud. You don't want to plug up your nice new core with rust! Your new radiator won't work worth a darn if it isn't getting any water through it.

Well, I can see it flowing in the rad so I assume it is flowing thru the pump, but good idea, I may just get a new pump.

Have you reverse-flushed the engine? If not, then the contaminates in the water jacket will seriously aggrivate the overheating.

Let the motor cool, then remove the upper and lower radiator hoses, and the thermostat. Stick a garden hose where the radiator hose attaches to the water pump. Turn the hose on, and you'll be amazed what kind of crud comes out of the thermostat housing. Let the hose run till clean water runs out of the thermostat housing. That will eliminate the possibility of crap in the water jacket causing the overheating. Buy a new 160 degree thermostat, and drill a 1/16" hole through the flat part of it. Refill with 1 gallon of antifreeze and fill the rest of the way with water. Let us know what happens.

Chip

Could it be a blown head gasket even if I don't see it steaming out of the pipe?
I know there is pressure in the rad, but I just assumed it was boiling.

Get it hot and stick a thermometer in the radiator. If it's boiling, should read 212. If it's lower, then check the compression.

GO BACK TO BASICS. The truck was designed to run properly as equiped. Thermostat OK? Water pump leakig out the bottom?