Radiator drain plug won't seal

[TLink FJ60]

While replacing my water pump, I removed my radiator and had it flushed. It was sitting out and dry for a couple weeks. Now when I put it all back together the plastic drain plug in the radiator leaks. There is a steady drip about 1 every second. I bought a new one at o'reilly's but it leaks the same as my old one.

Is there some type of seal or gasket or something that is supposed to be inside the radiator that the plug is supposed to seal against?

Advice?

 

[DFXR]

Have had similar problems with both stock and aluminum radiators. I used teflon tape and it solved the problem. Also make sure not to over torque the plug.

 

[TLink FJ60]

So, I had tried some red RTV and that slowed it down. Then I tried teflon tape, and that stopped it. Thanks.

 

[Trapper50cal]

New o-ring should solve it as well.

 

[TLink FJ60]

When you say o-ring, do you mean the rubber ring on the threaded plug itself? I got a whole new plug including it's rubber seal, and that didn't help any. That's when I posted on here. But I was wondering is if there is supposed to be a ring or rubber seat of sorts in the valve (not the plug) that the plug seals against. I haven't found any evidence that is supposed to exist.

My next thought, can you replace the valve? Is it welded to the radiator? I'm sure a radiator repair shop could replace it, but could I (no welding equipment)?

 

[Racer65]

Many of you with an aftermarket radiator will have this plastic drain plug. It's best to replace it every 10 years or so, because the single O-ring that provides the seal starts to give and it becomes the weakest link in your cooling system. If you wait until the plastic becomes brittle, it can break when you try to remove it, and then a 10 minute job becomes a 2 hour job.

It's also a good idea to put Teflon tape on the threads (which it did not originally have). You can buy this identical part at Auto Zone (Dorman 61112). The attached photo shows the original plug along side the Auto Zone replacement.

 

[MANUCHAO]

I dont trust those little plastic plugs..
I replaced it with a brass plug and some teflon and that solve the problem...

 

[dbleon]

I dont trust those little plastic plugs..
I replaced it with a brass plug and some teflon and that solve the problem...

yup......

 

[cruiser enthuiser]

Bumping this thread.

I've misplaced my drain plug (no body uses the term 'petcock' anymore apparently - go ahead and ask the girl at the parts counter for a replacement petcock and watch her reaction). I need a replacement ASAP.

Can anyone confirm thread size? Is 1/4" npt indeed correct?

Thanks in advance.

-Ed

 

[cruiser enthuiser]

Many of you with an aftermarket radiator will have this plastic drain plug. It's best to replace it every 10 years or so, because the single O-ring that provides the seal starts to give and it becomes the weakest link in your cooling system. If you wait until the plastic becomes brittle, it can break when you try to remove it, and then a 10 minute job becomes a 2 hour job.

It's also a good idea to put Teflon tape on the threads (which it did not originally have). You can buy this identical part at Auto Zone (Dorman 61112). The attached photo shows the original plug along side the Auto Zone replacement.

BTW, tried this one. It did not work for my '84.

-Ed