leaky temperature bulb in head

[kendall]

I'm trying to seal the nut that contains the temp. bulb and which the capillary tube runs thru on the block of my 1947 230 dodge. The original outer gland nut is missing and it accommodated the bulb nut which looks like 1/2" pipe thread but is slightly smaller and doesn't allow compression of another bushing within it and thus leaks. VPW can provide a new/used gland nut but I would have to pull the head and I'm not sure the stock o.d. and tread pitch is compatible with my new Edgy head. I attempted gasket making silicone on all surfaces without luck. Would heat from soldering destroy my gauge? Try silicone again? Thread sealer? JB weld? Go electric and retrofit my gauge?

[Don Coatney]

Suggest you contact Edgy for there recommendation.

[kendall]

Photo shows components. The threads are 'sloppy' in the head insert but you can tighten the nut by bottoming it out. But the coolant seems to leak at the capillary tube.

[DJ194950]

That temp sender requires another special fitting in the head first that has a tapered seat for temperature bulb.

DJ

[Plymouthy Adams]

dj is right...you need the correct adapter for the bulb will be needed, these are sold by gland nut size and Stewart Warner at any big box store ought to have it.  The taper of the bulb should be your seal when snugged up

[kendall]

I'm very fortunate to have found my original gland nut attached to a nipple removed from my engine months ago and stored in an old parts box. I was told that the nut is no longer made and difficult to find. I used a pipe extractor to remove the nontapered brass nut and now I'm good to go. I seem to relearn the same lesson over and over again. It's easier to make things worse than better.  Thanks for the input

[Jocko_51_B3B]

 

My original Dodge temperature bulb is on the left.

I bought a new brass fitting at ACE HW (photo on the right) to screw into the head but it lacks an internal seating surface for the tapered seat on the bulb to seal against. (In fact, the bulb slips completely through the new fitting.) So I can see that the new fitting I bought is wrong. Has anyone actually found the correct fitting (one with a tapered internal seat) at a big box store like Home Depot? Can someone post a picture of the correct fitting showing the internals? I'm also going to call Stewart Warner today, but I don't see anything on their website that looks like it would work.

 

  

Edited October 21, 2019 by Jocko_51_B3B

[Plymouthy Adams]

what you show is simply a reducing bush for pipe thread and does not incorporated the sealing collar internally as your sender requires.  AGAIN, I suggest you go to your local big box auto parts counter and ask to see the adapters in their Stewart Warner line of products....they should have what you need.  If not, ask for their catalog and buy it by specs.  These gland nuts are specific to application and not general plumbing supply items.

[Jocko_51_B3B]

 

I thought I had found the right fitting but it seems things are never that easy. 

 

My temp bulb is too large to fit through the hole in the fitting. The diameter of my temp bulb is .433 - .435 in. The hole in my new fitting is .393. I suppose I can drill out the fitting with a 7/16 bit (7/16  = .4375). The bulb might still seal even though the hole in the fitting will be 2 or 3 thousandths larger than the bulb. But I wonder why drilling out the fitting should even be necessary. Maybe the bulb diameters varied a little bit from the factory, some larger, some smaller.  I obtained the fitting from one of the well-known Pilothouse parts suppliers so I'm not sure who the original manufacturer is. Has anyone else encountered this problem?

 

  

Edited October 24, 2019 by Jocko_51_B3B

[DJ194950]

I had to drill one of those new fittings larger once.

I did it on my drill press and a clamped down vice on the drill press.

First I found a drill bit that matched the hole already in the fitting. I put that drill bit in the drill and lowered it to align the hole  (drill Not running) straight when I put the fitting in the vise and tightened the vise.

That assured the drill was directly centered to the hole. Then I put the drill bit in the drill that was the size of the temp bulb (or Slightly larger)  and drilled to the larger size.

 

The fitting worked well for me with Teflon tape on the larger thread part of the fitting and installed it and then the sender in the smaller part.

 

Done.

[Jocko_51_B3B]

DJ,

Thanks for the response. I'll drill it out with a 7/16 bit. Good to know that your temp bulb still sealed. That's what I wanted to know.

Glenn