Mysterious radiator hose connection

[LemonySoda60432]

Did I order the right radiator? I swear to god I cannot figure out what this hose connection is for!

 

[RichLo]

Replacement radiators are made universal so they dont need to make multiple different part numbers depending on what options a vehicle has. So they come with extra fittings and stuff that doesnt effect the function if its not being used.

 

[someotherguy]

Did I order the right radiator?

We dunno.. what in the world are you working on?

That's the heater core return line connection.. on SOME years of GMT400 trucks. Some years return to the water pump instead. So if yours didn't originally connect there, that's why there's a rubber cap provided..

Richard

 

[LemonySoda60432]

We dunno.. what in the world are you working on?

That's the heater core return line connection.. on SOME years of GMT400 trucks. Some years return to the water pump instead. So if yours didn't originally connect there, that's why there's a rubber cap provided..

Richard

I have a 1999 GMC C1500, kind of an oddball year, I know. May be why.

 

[east302]

I’d ditch the rubber cap that it came with - those are usually cheap and will crack/leak fairly soon. Post #7 in this thread has a product recommendation for a replacement silicone cap:

Coolant loss 5.7 vortec

Hey guys do you notice these 5.7 vortecs burning coolant because of the "open" coolant system? I read you get some evaporation because of the overflow tank having that open down tube. I have lost maybe 1/2 inch of coolant out of the reservoir in the past month. Last month i did a new fel pro...

www.gmt400.com

 

[RichLo]

I have a 1999 GMC C1500, kind of an oddball year, I know. May be why.

That would have been good to know on the first post. If its a GMT400 body then it was built in 1998 and just carried over to 1999. I'd bet you got the wrong radiator, check if its the same part number for a 1998. In the future, order parts for a 1998 instead.

 

[someotherguy]

That would have been good to know on the first post. If its a GMT400 body then it was built in 1998 and just carried over to 1999. I'd bet you got the wrong radiator, check if its the same part number for a 1998. In the future, order parts for a 1998 instead.

1999 "classic" and yes order for 1998 as it's less confusing to the parts people/websites.

I wouldn't figure it's the wrong radiator, or it simply wouldn't fit the core support. Big difference between a GMT400 and a GMT800.

Most of the GMT400 aftermarket radiators I've seen have that connection. Many year models of GMT400's do use it for the heater core return line.

And, good advice from east302 on replacing the cap with a silicone piece. I've seen those rubber caps fail, even in less demanding environments than an engine compartment.

Richard

 

[LemonySoda60432]

1999 "classic" and yes order for 1998 as it's less confusing to the parts people/websites.

I wouldn't figure it's the wrong radiator, or it simply wouldn't fit the core support. Big difference between a GMT400 and a GMT800.

Most of the GMT400 aftermarket radiators I've seen have that connection. Many year models of GMT400's do use it for the heater core return line.

And, good advice from east302 on replacing the cap with a silicone piece. I've seen those rubber caps fail, even in less demanding environments than an engine compartment.

Richard

Thanks for the advice man! It's my first car so I am still learning about certain tiny details and how to order correct parts.

 

[someotherguy]

Thanks for the advice man! It's my first car so I am still learning about certain tiny details and how to order correct parts.

No worries. There's not a lot of 1999 "classic" models out there - and that's what yours would generally be referred to if it's still the 1988-1998 body style, a.k.a. "GMT400" trucks that this site is focused on. Since 1999 officially was the next generation of trucks, GMT800's, which ran from 1999-2006 (and 2007 "classic"), when you shop parts for a 1999, it's easy to find the wrong parts for yours. That's why picking 1998 makes that far less of a problem.

Richard

 

[Pauly1119]

Did I order the right radiator? I swear to god I cannot figure out what this hose connection is for!

I had a similar one on a suburban a few years back and that plug would fail for some reason and radiator fluid would spill out. I started to carry a extra plug in my glovebox.