Coolant leak

[JDegenerate]

96 4.0 - Coolant leak from the line that runs into the rad just below the cap. I temporarily fixed it before by using Teflon tape around the threading of the fitting that goes into the rad, but that wore down as I expected and leaked again. I think it's the plastic that fitting goes into that's worn away - what should I do about it? I don't want to replace the rad over that.
It's way too hot in GA for this crap lol.

 

[koda2000]

I believe you're talking about the hose that goes from the radiator to the overflow tank. Try replacing the hose. With age they can rot, crack and/or swell and leak. There's nothing special about the hose, so any auto parts store will have stock hose to replace it. You can also add a spring clamp to it to keep it tight on the nipple.

If this hose does not fit tightly, not only will it leak it will suck air into the radiator, instead of cycling coolant to/from the overflow tank. This can lead to low coolant level in the radiator while the overflow tank remains looking full.

 

[Turdle]

If it is leaking at the overflow tube to radiator, the overflow hose and or reservoir inlet piping is probably clogged. You should be able to blow bubbles into the reservoir easily with that hose. It needs to free flow or coolant loss and overheat may result.

You will need to drain it, flush it repeatedly and use a shop vac to get the crud out, or, it will continue to recycle thru the system and clog it again. Might be time to flush the cooling system as well

What confuses me though is the use of the word "threads"

Are you sure it isn't a transmission line you are looking at? does the line in question point directly at the engine from radiator, or, does it point to the passenger side of truck?

 

[Turdle]

picture of radiator courtesy of www.rockauto.com

is the leak at the tiny black nipple pointing right, ( overflow) or is the leak at one of the holes which is plugged with a hex shaped plastic dealio ( transmission) ?

 

[JDegenerate]

No, it's not the overflow tube, it's at the metal fitting below the cap in that picture.

 

[JDegenerate]

So it is a transmission line leaking. It is a metal fitting the hard line runs into, and the leak is coming from behind that metal fitting. By threads I mean the threads on that fitting, it's like a bolt.

 

[Turdle]

well,
You can just bypass that if you have an auxiliary cooler. Otherwise you need a new radiator.

 

[koda2000]

If it's leaking from where the transmission line attaches to the radiator you need a new radiator. They're easy to change on a 4.0 and can be found for around $100-$120 on-line.

BTW, bypassing with an aux trans cooler isn't going to stop your coolant leak.

 

[Turdle]

If it's leaking from where the transmission line attaches to the radiator you need a new radiator. They're easy to change on a 4.0 and can be found for around $100-$120 on-line.

BTW, bypassing with an aux trans cooler isn't going to stop your coolant leak.

Yeah, I was assuming it is trans fluid leaking there. How could coolant leak from the transmission fitting?
edit, I see now. The trans lines run through the tank.

Koda is correct.

 

[koda2000]

Yeah, I was assuming it is trans fluid leaking there. How could coolant leak from the transmission fitting?

The trans fittings provide a path for the transmission fluid to enter the radiator and flow through a small tank, which sits in coolant to help cool the transmission fluid. The internal tank prevents the antifreeze and trans fluid from mixing together. Apparently the gasket/seal that is supposed to seal the trans fittings to the radiator has failed.