Re: Temperature gauge line to head???

Posted by Packard Newbie On 2018/9/10 15:33:49

Well, now I'm thoroughly confused!!!! Brian, you said the thread size was 5/8-18 fine. I went and bought a tap that size and it is, obviously, 5/8"OD. I have the hole drilled out to 1/2" and I can see the collar in behind the hole. If I put a thin, flat screwdriver in at an angle, it catches on the collar. The sender unit for these gauges look like they are about 1/2" in diameter and a 5/8" follower nut would sound about right. Why does this suddenly sound 'way too big'??? 5/8" is .625, nothing to do with pipe thread, which is huge, compared to. I did get with Wolf's and they do the repair for $165 which is okay and they replace the entire capillary tube from the back of the gauge to a new sender bulb. When I mentioned 5/8-18 for the follower nut, they knew right away what I was talking about - it seemed commonplace to them.
Can somebody 'set me straight' here before I ruin the head???
What am I missing???
Also, Ross - can you measure the OD of the threads on the nut you have so we can see if I have already drilled it too big??
Keep in mind Brian, when I say I have the hole drilled to 1/2", I am not saying 1/2" NPT, just a 1/2" bit (.50)