When I put a new radiator in my 72 Skylark I got one that was suggested by folks here. Not sure what it is for on the radiator but right below the cap/filler neck there is a capped off nipple like opening. What is that for? Today was my first MAJOR voyage after the many roadblocks to getting my car on the road. Did the Pumpkin Run Nationals here in Cincy, about a 40 min drive each way with some sitting traffic. Well this morning our first real cold morning I started the car and let it run for about 5 min or so and that stupid nipple that has what I think is a cheap rubber cover and clamped on was LEAKING. I have to assume that it needed to be tightened down a hair which I did. No more problems the rest of the day.
It’s probably a heater return line-a lit of the radiators that fit A and G bodies have them. Apparently something out there needs it, so they all get it with a cap. Patrick
Is that the plastic/aluminum 1-core radiator? Probably same one I have since it has the same plug... guess I'll need to watch for leaky nipples.
That plug will blow constantly. I've had to clean up coolant twice because of the rubber caps dryrotting and cracking. I went to an all aluminum welded radiator in my regal. Looks spiffy and no stupid rubber caps. Its got an o-ring bolt. Just keep an eye on it and keep a handfull of those caps in the glove box.
No, not the overflow. There is a separate jacket/hole a couple inches below the cap that has a rubber plug over it.
Gotcha! Now that I think about it, I replaced the radiator in my Yukon and it DID have that nipple.... Below the overflow nipple..
The rad fits many vehicles. Some connect the heater hose directly to it. those caps fail in less than a year.
Just rubber coolant caps. They come in assorments hanging in the help/dorman isle of most parts stores.