Cooling System Question

[BT3583]

So I was out driving the Deuce around yesterday, gave her a good ride hills and all that good stuff. Got to where we were going let her cool down and shut her off. When walking back to truck noticed antifreeze leaking from the cap. Started her up and the leak stopped, temp has been holding at 180 all day. We drove some more no issues. Once I got her back in garage while cooling down I noticed the radiator seemed cool. The top tank and heater core lines are hot, but the middle to bottom of radiator seems cool. Coolant looks clean. The water line on top was hot the line on bottom cool. Could there be a blockage and shouldn’t the truck have been running hot? Thanks for the help.


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[NY Tom]

Not sure when you last filled or topped off your rad. Or if you filled it in cold weather and it is warming up. These trucks seem to puke coolant until they find their happy spot. Filling mine to the top and driving it the first few times coolant leaks out from the overflow pipe. Sounds like the temperature is OK. These trucks run pretty cool in my experience.

 

[BT3583]

Not sure when you last filled or topped off your rad. Or if you filled it in cold weather and it is warming up. These trucks seem to puke coolant until they find their happy spot. Filling mine to the top and driving it the first few times coolant leaks out from the overflow pipe. Sounds like the temperature is OK. These trucks run pretty cool in my experience.

Thanks NY Tom. It looks clean, level is at the bottom of filler neck. I’ll just keep an eye on things. Also appreciate your input on my leaky HH post. Will be tackling that one here shortly.


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[NY Tom]

No problem I kept filling mine up and wondering what was wrong as it would leak out. Back then the overflow line was broke off so it would come out below the neck and get sprayed all around by the fan and belts. The hole on the side cover is where it would come out and look way worse than it was - LOL. Then after some searching on here I stopped filling it and it found a level and stayed there.

We live and we learn about these trucks and I am no expert. I just keep reading and learning from the others on this site.

 

[BT3583]

No problem I kept filling mine up and wondering what was wrong as it would leak out. Back then the overflow line was broke off so it would come out below the neck and get sprayed all around by the fan and belts. The hole on the side cover is where it would come out and look way worse than it was - LOL. Then after some searching on here I stopped filling it and it found a level and stayed there.

We live and we learn about these trucks and I am no expert. I just keep reading and learning from the others on this site.

I am certainly learning a lot. Been doing lots of reading on here along with the TM’s. Looks like I will also be doing transmission and transfer case seals. Probably have close to 75-100 miles on her and now and she has started leaving her mark where we park. LOL

 

[NY Tom]

Yeah I had to do them as well it's a signature. Something went wrong on the transfer case output seal - of course - so have to do that one over again.

 

[frank8003]

I am certainly learning a lot. Been doing lots of reading on here along with the TM’s. Looks like I will also be doing transmission and transfer case seals. Probably have close to 75-100 miles on her and now and she has started leaving her mark where we park. LOL

This is a 50 year old machine worth every penny paid.........

Don't do a thing to anything. Keep checking everything.
Driver Her 200 HOURS and call back.
This ain't nothing like one measures with miles, She nicest diesel I ever saw. Run Her.
One can not save Her forever unless you treat Her right.
She designed to come off assembly line and RUN until She is taken out.
She is tactical military vehicle to do work for our people. Give Her some work to do.
She needs to RUN ....

 

[Karl kostman]

You dont cool your trucks engine by shutting it off! If anything that can be very hard on the turbo because of no oil pressure ie. oil flow to the turbo. Next time you want to cool your truck off just let it idle for 5 minutes then you are keeping the cooling system active in its job, cooling off your engine!

 

[M37M35]

When walking back to truck noticed antifreeze leaking from the cap.

Was it leaking from under the cap?
Or is there a crack in the overflow tube or neck?
If it's coming from the cap, it might not hurt to replace it.
NAPA 703-1418
GATES 31308

Could there be a blockage and shouldn’t the truck have been running hot?

There could be, but yeah, I'd expect it to run hot if so.
Have you verified the engine temp with an infrared thermometer?
Have you ever flushed the cooling system?

These trucks seem to puke coolant until they find their happy spot. Filling mine to the top and driving it the first few times coolant leaks out from the overflow pipe. Sounds like the temperature is OK. These trucks run pretty cool in my experience.

Same here. I added an expansion tank to mine to catch what gets pushed out. It's a cheap and easy upgrade.
While towing up hills in the hot summer, mine never gets over 195. Any other time it's 180.

 

[BT3583]

Was it leaking from under the cap?
Or is there a crack in the overflow tube or neck?
If it's coming from the cap, it might not hurt to replace it.
NAPA 703-1418
GATES 31308


There could be, but yeah, I'd expect it to run hot if so.
Have you verified the engine temp with an infrared thermometer?
Have you ever flushed the cooling system?


Same here. I added an expansion tank to mine to catch what gets pushed out. It's a cheap and easy upgrade.
While towing up hills in the hot summer, mine never gets over 195. Any other time it's 180.

Thanks M37M35.

It was leaking from under the cap, I was planning on replacing figure certainly can't hurt. I always let her idle and cool down for about 5 min or so after a run. It was probably sitting for about 15 min after killing engine when we walked back over to her and noticed the leak. I'm pretty sure it's just finding it's happy place with the coolant level, Saturday was probably the warmest it's been so far since I've had her. Temp gauge stayed at about 180 the whole time.

I have not hit with an infrared thermometer yet, I will do that the next time I have her out. I have not flushed the system out, it was done before I got the truck. It's still nice and green in the filler neck and when opening the draincock on the bottom of the radiator it was green but not as green. I'm sure it can't hurt for me to do a flush.

I Like the expansion tank idea.

Thanks!

 

[frank8003]

hours under load will save her