Thread sealer?

[carguy300]

I had to buy a new temp sensor for my water pump housing, and a heater hose nipple, should I apply any type if thread seal on either one.? I know the sensor is brass, it was difficult getting the old one out, didnt appear to have anything on the threads. I want to make sure and I get it right the first time, no leaks!

 

[Big_John]

Sensor needs to be put in dry because it needs to ground to the housing or it won't work.

 

[carguy300]

Good point! I didnt think of that, never had to change one. What about the hose nipple, does that need anything on it?

 

[Toolmanmike]

Sensor needs to be put in dry because it needs to ground to the housing or it won't work.

So many don't know this. Thanks for educating the masses. Tapered pipe thread doesn't need sealer.

 

[carguy300]

This is why I appreciate the guys on this site!, years of knowledge so easily shared!

 

[1970FuryConv]

I have used thread sealer on Aluminum intake manifolds for heater hose nipples and temperature sending units. I used it because I thought it sealed gaps between the TSU or hose nipple threads and the manifold threads, not places where metal was in firm contact with metal. I further thought the remainder of the thread sealer was pushed out of the threads either below or above the nipple. I never had a problem with the TSU not grounding or either part leaking. Plus I thought using thread sealer protected against over-tightening and stripping aluminum threads. I could get it nice and firm, then stop because I knew it wouldn't leak.
360 Small Block with AC compressor

 

[carguy300]

I have used thread sealer on Aluminum intake manifolds for heater hose nipples and temperature sending units. I used it because I thought it sealed gaps between the TSU or hose nipple threads and the manifold threads, not places where metal was in firm contact with metal. I further thought the remainder of the thread sealer was pushed out of the threads either below or above the nipple. I never had a problem with the TSU not grounding or either part leaking. Plus I thought using thread sealer protected against over-tightening and stripping aluminum threads. I could get it nice and firm, then stop because I knew it wouldn't leak.
360 Small Block with AC compressor
View attachment 620634
View attachment 620635

I noticed new heater hose nipple, what did you use on threads?

 

[Big_John]

I have used thread sealer on Aluminum intake manifolds for heater hose nipples and temperature sending units. I used it because I thought it sealed gaps between the TSU or hose nipple threads and the manifold threads, not places where metal was in firm contact with metal. I further thought the remainder of the thread sealer was pushed out of the threads either below or above the nipple. I never had a problem with the TSU not grounding or either part leaking. Plus I thought using thread sealer protected against over-tightening and stripping aluminum threads. I could get it nice and firm, then stop because I knew it wouldn't leak.
360 Small Block with AC compressor
View attachment 620634
View attachment 620635

I think that using it sparingly with the aluminum manifold is a good idea. Sparingly is the key word and if done right, the sender will squeeze out enough of the sealant to make a good enough ground. Just being aware that if there is an issue, that is the first place to look.

With the cast iron manifold, the brass threads of the sender wouldn't need to have sealant. The brass threads distort and seal nicely to the tapered NPT pipe threads in the cast iron without sealant. That is by design... and with no sealant, no need to worry about getting a good ground. A lot of folks over-tighten fittings like this, and actually make them leak.

The heater hose nipples are plated steel to cast iron. I've done those both ways... If I have the sealant handy, I'll probably slather a little on (and get it all over my hands). It's sure not going to hurt, but I've never had one leak that I didn't seal either...

 

[68PK21 440.6bbl]

Pipe dope...

Pipe Dope 101: The Secret to Leak-Free Plumbing Projects

Pipe dope refers to pipe threading sealants used for plumbing connections. Pipe dope is used on water and gas pipes. Read this guide to choose the right one!

plumbingnav.com

.

 

[1970FuryConv]

I noticed new heater hose nipple, what did you use on threads?

Permatex High Temp Thread Sealant 7010664