Tapping Water Outlet for Temp Gauge

Ron/IA

Well-known member
There has been much discussion lately on installing a temperature gauge (which I am going to do). A lot of good info was passed along.

However, I was wondering if anyone has tried to modify their water outlet themselves to accept the 1/2" NPT of the water gauge instead of purchasing said modified outlet or similar radiator hose pipe from the vendors.

If so, what procedure did you use?

Thanks,
 
I've seen it done, but it leaves very little thread for the guage. You simply drill the hole for the pipe tap size, then tap it. If you move the tap side to side while tapping, you will have a loose fit and probably a leaking fitting. If you are going to do you own, then it would be better to buy the right fitting for the thread and braze it to the housing after drilling the hole.
 
I use the upper hose pipe. Upper water necks break easily. I can see no reason to run the risk of breaking a fifty dollar drilled and tapped special outlet. Like Tom says the original upper neck is sorta thin. I feel that a drilled and tapped upper neck is MORE noticable than thje upper hose pipe connection. If a person decided to go back original at a later date, the upper hose pipe connection would be easier to un do. I can see no advantage to a drilled and tapped upper water neck. I always prefer the easiest least invasive approach. Just my thoughts, do it the way that you prefer.
 
Tom & Purdy - Thank you very much for your thoughts; they make sense.

I know the material available for tapping in the water outlet is thin, and I have thought of using a cast iron pipe fitting to be brazed/welded to the outlet.

I was just wondering if there was some "trick" I hadn't thought of, but it appears not.

Thanks again,
 
On both of my cars I drilled and tapped the water outlet and have had no problems as of yet. If I was going to do it again I would just buy the outlet that is already tapped.
 
I drilled and tapped mine without a problem. The probe I used had a 1/8" pipe thread so getting enough threads in the thin wall wasn't an issue.
 
Thanks guys; I was almost sure someone had done this themselves. Glad to know yours are working satisfactorily.

Sparky - Can you tell me where you got the temp probe with the 1/8" pipe thread? Ones I have seen so far are 1/2" NPT.

Thanks,
 
My temp gauge came with an 1/8" pipe thread temp probe. It also came with adapters for 1/4, 3/8, & 1/2.
 
I think the best solution is to braze a threaded fitting to the outlet. This is the one that was on the chassis I used for my Deluxe Delivery. Well thought out on angle and placement to accomidate the longer probes on some sending units. Rod
 

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How about splitting the upper hose and using a tee with pipe nipples/clamps?

A8273-7940.jpg


$13.95 as shown.

You butcher a cast iron piece or you butcher a replaceable hose?

Joe K
 
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Then there is always this one with ports already in it. Don't "ruin" your original, uses your regular hoses & clamps.

(Picture posted especially for Tiny!)
 

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I drilled and tapped mine 4 years ago and no problems yet. Just be careful like TOM sez and make sure you drill and tap straight 1/4 in.on mine
 
Rowdy - I agree the tap install on your water outlet is very neat.

Joe K - I am probably going to go with the tapped pipe type you illustrated. Simple and cost affective.

Carl G - The unit you show is a machined masterpiece, but at $90+; it is more than I want to budget for. Anyway, I can get gauge, gauge bracket, and tapped pipe for less than $90. However, this unit would fit specific applications for those who need it.

By the way, I have been doing some more shopping for temp gauges, and have found some with different pipe tap sizes.
Thanks,
 
Thanks guys; I was almost sure someone had done this themselves. Glad to know yours are working satisfactorily.

Sparky - Can you tell me where you got the temp probe with the 1/8" pipe thread? Ones I have seen so far are 1/2" NPT.

Thanks,

Since I have a 12 volt system I was able to use a Stewart Warner electrical gauge which has a small diameter probe. If you have to use the mechanical type gauge you may be stuck with the larger threads.
 
How about splitting the upper hose and using a tee with pipe nipples/clamps?

A8273-7940.jpg


$13.95 as shown.

You butcher a cast iron piece or you butcher a replaceable hose?

Joe K

This or the probe adaptor that fits right in the hose is the way I'd also go.
 
Before I purchased the Vintage Precision outlet, I drilled and tapped my water outlet with no problems. I would suggest, because of the thin wall and minimal threads, that you seal the threads with JB Weld to insure that you'll have no leaks.
 
Thank you for the JB weld suggestion (good thought). Also, the picture of the install (very neat and simple).

Now all I have to do is make up my mind (and with my mind, that isn't easy sometimes).

Thanks,
 
If you're using a V-8 water pump, it's easy to put the probe in the block off.
 

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