Stripped threads in water pump heat hose connection

Was looking at putting the new nipple on my water pump on my 440 engine. I notice that the nipple was going on very tight. Took it off and notice metal shavings and screwed up threads. I am guessing it was already like this. I think I am going to have to get a tap and redo the thread. Are there any gotchas for doing this on the water pump?

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Those are NPT pipe threads. They take a special tap and are a tapered hole. I definitely wouldn't do that job still attached to the engine.

Either 1/2 or 5/8 NPT. Tap it just like you use a bolt tap. Maybe use a long extension to tap it still on engine.

Agree it is best done off the engine to keep the chips out of the coolant. Since the threads are tapered you should be able to run the tap a little deeper than original and restore adequate threads. It will take some care to get the tap started right.

A good hardware store will have individual PT taps. Or get a complete set at HF for reasonable cost. I have found the HF taps to be fine for clean up and touch up work.

If you decide to tackle the other nipple while it is out heat helps... heat the nipple cherry red and touch a candle to it while hot. Let cool and it should come right out.

just a little caution on restoring tapered pipe threads. try to only go a thread or 2 deeper if you can. if you go too deep, the casting will have to be machined to restore adequate clearance from bottoming out on the shoulder[end of the threads] of the fitting. when the shoulder bottoms out, the fitting WILL leak. over 42 years as a machinist, i have had to repair many, many castings that have been "fixed" by tapping pipe threads deeper to restore boogered up threads, and sometimes castings are ruined because there is not enough material to reface the casting after cleaning up the threads.

Glad I started this thread. Maybe I am overthinking this whole thing. I don't even want to connect the heater hoses up. I was just planning on putting the nipples on and then capping the nipples. Would there be a easier way to just seal up the holes? I am worried that tapping the hole is going to be more complex then I originally planned. Looking at the hole you can see where part of the hole was already damaged. After listening to the guys on hear I am worried I am always going to have problems with it leaking.

If you're not using the heater then I would just plug the openings with the appropriate size NPT plug after straightening the threads up. They even make the plugs with an allen drive. It will be a much cleaner and reliable solution.

You might JB weld a plug in there as is. if you do tap there might be room to put something down in there to catch the shards then pull em out with a pencil magnet or pull the impeller pump itself so you can get in the housing & catch em that way

While I agree with all the above threads on easily repairing the casting. Consider it's also an easily replace part. If you go through the trouble of removing it. Unless there are dates on it you are interested it. I'd just replace it with another used unit.

Put a some grease on the tap most of the chips will stick in that.

If you aren't going to connect the hose up , or even do it in the future then just coat a plug with JB Weld , after leaning the threads of any foreign substance and screw it in till it stops and let it cure.

Grease the tap. Give it 2 turns. Clean the threads. Apply Teflon pipe sealant to the plug. Done in 20 minutes
No big deal.
Doug