General fitting question
 

I own a 1997 K2500HD. I was looking at the radiator the other day and found a blocked off fitting below the cap, and overflow hose(see photo). Engine is a 5.7 Vortec. What is it for/go to?? Reason I'm asking is the temp never goes above 180 on the guage, I have a scent of antifreeze, the level keeps going down, but nothing keeps going up, and I've pressure tested all areas and haven't found any major leaks. Any help or guidance is appreciated. Also for some reason my phone keeps upside downing my photos, so my apologies.... Jeff

Re: General fitting question
 

I'm working on my C2500 right now, funny, I found a rubber plug/cap laying on the intake that looks very similar to the one you're asking about. I'll see if there's been anything attached to the radiator and let you know.

Re: General fitting question
 

Here's the plug I'd found on the intake, it's probably 3/4' in diameter. I looked, and don't have the tap under the overflow like in your pic.

http://i374.photobucket.com/albums/o...ps82157e82.jpg

I did a quick search that lead me to a Ford Forum, they claimed it went to the throttle body, even most said it was unused.

Search "Double overflow on radiator" if you need more.

Re: General fitting question
 

I have the same non used port on my replacement HD Cooling aftermarket radiator. My guess is that it is used on other applications where this radiator could be used. I seem to remember a similar port on my brother-in-laws 77 C10. It was a coolant return line from the intake manifold I believe.

Re: General fitting question
 

I'm surprised no one commented on the fact that it's for a heater hose. It runs from the rad to a heater core fitting on the firewall. The other side of the heater core fitting connects to a fitting at the rear pass. side of the intake manifold. At least that's what that rad fitting was for on the early 90's trucks. Maybe you have an older rad on newer truck that didn't need that arrangement.

Re: General fitting question
 

ihave the same thing on my 97 and it still has the orignal rad.

Re: General fitting question
 

It's a aftermarket radiator, To cut down on different part numbers, They include the heater hose connection even though your model doesn't need it.

That's the rubber bumper for the intake silencer, The plastic box that says "Vortec" on it. The bumper keeps it from rubbing the upper intake manifold.

Re: General fitting question
 

My radiator is the original. Some hoses have been replaced, but almost everything under the hood reflects the 119k the truck has. I'm wondering if one of the POs might have had a set of hoses replaced, which would explain why the plug might be there. I want to keep the truck as stock/factory as possible. I just wasn't sure if there would be a port on my engine that has a plug like that on it. I'm not seeing a hose routing diagram.....

Re: General fitting question
 

You sure that's the original radiator? I ask because I just replaced the one in my 97, and the original did not have the extra outlet, but the replacement came with the outlet and it was capped off just like your pic.

Re: General fitting question
 

That is not the original radiator, Note the adaptor bushings on the transmission cooler lines.

Re: General fitting question
 

Good to know, thanks! One more thing to add to todays list :lol: