Need expertise on water union installation sealing?

Hey Guys,

I could use your expertise on the installation of a brand new water union on my 79 308GTB.

Here are the details: The old water union had to be drilled out and the hole re-tapped. That in it’s self went very well.

Now the brand new one screws in like a champ. My only concern is, is that I don’t want it to leak around the threads. Now since both the engine block and the new water union
(Water union: return heater hose nipple off the drivers side engine) are both made of aluminum, would it leak anyway? Since they’re both aluminum would the surfaces bond together better? As I removed the old water union (nipple), it didn’t look as if the factory used any bonding material. It just looked as if they screwed in into the engine block.

Would you recommend using a lithium white grease or plumber (Teflon) tape?

Any thoughts?

Thanks Guys,

Chris.

 

That might be something I'd consider,

I was kind of hoping that since the threads are in fact tapered, I could get away with just a simple lube.

But thanks for the advice, I'll follow up.

Aprrecaite it.

Chris.