Coolent drain thread repair in lower tank / steering gear housing

[Genseal]

Would like to know if anyone else has had to deal with "lost" threads in the coolent drain of the lower tank. I did chase the threads with a tap, but didn't get to any "meat" until out of tap threads. I can get the 3/8" plug in and "maybe" snug, but not sure of seal and will need a nut welded on top of the square stock of the plug. Any ideas? Thanks

[Urbish]

You could tap it for the next larger size and either: install a reducer or use a larger plug. The Cub has a non-pressurized cooling system, so basically anything that will plug the hole and not fall out would be okay. I've gotten away with wrapping an excessive amount of teflon tape on a plug in this type of instance and it worked fine. I would NOT do that on a pressurized system. Check your cap. Some people do install a low-pressure cap on their Cub.

[Genseal]

So, there should be enough material on the boss that the plug goes into to enable drill/tap of 1/2" tapered pipe threads?

[Urbish]

I've never done it on a Cub, but yes, I believe so. A 1/2NPT tap is .141" larger than a 3/8NPT tap.

[inairam]

I went up a size on one or two cubs. There is enough material.

[Genseal]

Thanks for the replies. I will be increasing the plug size to 1/2". I've included a pic of the temp repair that has worked forn 7 years. Am in the middle of a rebuild/paint, so want to fix it right this time.

cub.pdf

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[Urbish]

Yikes. That is definitely ready for re-tapping.

[tnestell]

While we were running in The Great Race, a 10 day antique rally, there was a 1931 Auburn Boattail Speedster. It lost a water pump bushing or bearing. They went to Home Depot and bought a hardwood dowel, drilled it out and installed it in the pump. They ran the rest of the race that way. Apparently the wood swelled and sealed. Guess that is why Genseal's temporary repair worked.

[staninlowerAL]

Alternate to drilling and tapping to larger size is to use a brass 1/2 tubing x 1/2 npt adapter. The tubing threads will thread into the bolster/drain (you can use a sealer since it will not have to be removed) and cap with a 1/2 npt cap.

[John *.?-!.* cub owner]

I was needing thaq part for my loader cub, and found one somebody had messed up trying to drill it out, and it had a cutout where a drill bit had cut into the side. I coated the threads of a pipe nipple with a liberal application of JB Weld, and screwed it in, plus adding a little more to the hole. After the JB Weld cured good I added a pipe cap, and been using it that way for years.

[Donegal Cub]

Had the same problem on my '48 coated the threads with gasket maker and screwed it in although not tight it is doing the job noe for the last 8 years. As Urbish said as long as it doesn't fall out or leak there is no pressure on it.