Transmission Cooler Fittings (Question)
 

Background: PO installed an external transmission cooler mounted several inches in front of the radiator. The lines were removed from the radiator and re-routed up the front of the radiator where 3/8" fuel hose was slid over the inverted flares leaving the nuts intact.

Problem: When towing I get the smell of burned rubber. I suspect the external is undersized, and being so far from the radiator, gets little air flow from the fan.

Planned solution: Re integrate the radiator cooler, and run the external cooler in series.

Situation: External cooler has 3/8" hose barbs. I'm trying to find the correct 5/16" inverted flare to 3/8" hose barbs, both for the radiator, and the original metal line. I ordered Jegs 60340 which is the wrong thread.

I've found Hayden 393 from many sources on the internet. But I can't, for the life of me, find the hose barb size. I need it to be 3/8".

Does anyone know for sure?

Re: Transmission Cooler Fittings (Question)
 

I would not use an external cooler only. If you tow, you will not get enough cooling from that alone. You need the one in the radiator too.

Re: Transmission Cooler Fittings (Question)
 

Yeah, I know. It was that why when I acquired the truck. I'd like to reintegrate the in-radiator cooler along with the external cooler.

But I don't want to cut the steel likes, I'd like to use adapters to run a 3/8" hose. The Hayden 393 looks to be the right fitting set. But what diameter is the hose barb?

Re: Transmission Cooler Fittings (Question)
 

I don't know, but I would guess it is 5/16-but might be 3/8. There is probably a reason that the radiator cooler is not connected-like it leaks to water. Is it plugged off or open?

Re: Transmission Cooler Fittings (Question)
 

I would run some water through it first are even have it flushed good before using it. Good call on checking it first before using it.:chevy:

Re: Transmission Cooler Fittings (Question)
 

The ends were open. It does not leak. I've already run fluid through it. I was surprised how clean it was.

The reason it's not used, I suspect, is whomever installed the external cooler simply didn't know any better.