[grivera]

So I started up the 69 Lemans today- engine runs great for the short time I ran it. When I acquired the car, it had braided lines from trans to the radiator cooler, and fittings in the cooler side that the braided hoses attached too. I’ll admit, when I disassembled, I didn’t take note of the boogered up cooler fittings. Fast forward and I installed factory replacement hard lines. Upon startup, both top and bottom were leaking badly. I tried tightening slightly and it stripped the threads. These weren’t cross threaded and I didn’t torque down too much. I left the project alone for the night but snapped a pic of the threads. Kinda looks like the inverted flare is jacked up too. The line fittings look great on both lines. And no, they were not cross threaded on way in-went in nicely.

Can these be repaired at home? Need suggestions as I’ve never seen this before.

[indymanjoe]

no idea but i have used thread chasers. they dont cut new threads but clean up the old ones. i had to "clean" all the threads in my aluminum e-heads and it was a life saver.hth's

[gto4ben]

Yes, they appear damaged. I
d get an inverted flare male to female of suitable size and use the male end towards the radiator. It kind of looks like that was done in the past since without tubing, it could gall the flare portion like you see.

[grivera]

Originally Posted by indymanjoe

no idea but i have used thread chasers. they dont cut new threads but clean up the old ones. i had to "clean" all the threads in my aluminum e-heads and it was a life saver.hth's

Thanks- I have a thread chaser set but that still leaves the damn inverted flare!!

Originally Posted by gto4ben

Yes, they appear damaged. I
d get an inverted flare male to female of suitable size and use the male end towards the radiator. It kind of looks like that was done in the past since without tubing, it could gall the flare portion like you see.

Will give that a shot - thanks for the tip! Something like this but need to learn the TPI
https://a.co/d/iFwKn50

[grivera]

Originally Posted by indymanjoe

no idea but i have used thread chasers. they dont cut new threads but clean up the old ones. i had to "clean" all the threads in my aluminum e-heads and it was a life saver.hth's

Thanks- I have a thread chaser set but that still leaves the damn inverted flare!!

Originally Posted by gto4ben

Yes, they appear damaged. I
d get an inverted flare male to female of suitable size and use the male end towards the radiator. It kind of looks like that was done in the past since without tubing, it could gall the flare portion like you see.

Will give that a shot - thanks for the tip!

[Tim Corcoran]

A good radiator shop could solder in some new fittings for you. If they are stripped a doubt they can be salvaged

[steve25]

By the time you yank out the Rad to have a Rad shop do such work you would be better off just installing a separate trans cooler which would extend trans life better then the stock in Rad cooler anyway.

[grivera]

Agreed- the local shop charged me $85 just to pressure test and clean the radiator - and did a poor job at cleaning it - can’t imagine what they’d charge to replace the fittings.

I found the fittings that were in there previously - NPT into the radiator and male AN to the braids hose. I suppose I can try NPT to female AN fitting and maybe it’ll seal in the boogered up threads.

Anyone know what size NPT that would be? The correct line fitting is 1/2x20

[Shiny]

I'm pretty sure an inverted flare fitting has straight threads. It appears your flare seat is damaged and the threads are stripped, correct?

You are proposing a tapered male pipe fitting, correct? Since your female flare fitting is useless as-is, is there enough meat to go a size larger with an NPT tap on the radiator side? If you can get NPT threads cut, maybe you can get by. I don't think cutting straight female threads or chasing the existing ones, then trying to use a male NPT fitting will help, but that's just my guess. Definitely better odds if you use a tapered NPT tap in the buggered fitting. And you could try teflon tape if you go this route.

[grivera]

Yes the line fitting are straight threads and they were ruined by the NPT adapter I posted. It gets tight pretty quickly when I thread it in. Since it was previously in this space and is what ruined the threads in the first place I think it can’t hurt to give it a try. It had teflon tape on it previously as well. I’m just learning this as I troubleshoot the leak. I hadn’t thought about tapping it for NPT. DoI s anyone know the size NPT is that can be threaded partially in 1/2 x 20 straight threads, like the one in pic?

[zippy]

Have you tried chasing the threads? And installing the straight inverted flare adapter. If it threads in enough to hold, but not seal, JB weld the adapters in maybe? Not like you have anything to loose there. Fixed many things with JB

[grivera]

Originally Posted by zippy

Have you tried chasing the threads? And installing the straight inverted flare adapter. If it threads in enough to hold, but not seal, JB weld the adapters in maybe? Not like you have anything to loose there. Fixed many things with JB

I chased the threads this morning and the tool fits a little loose in the threads. Haven’t retried torquing down the line fittings again.

[Dragncar]

OK, I would not JB Weld the fittings in at this point. Because once you do it you are committed. If it does not work you will not be able to get it clean enough to solder. So, solder in the steel adapters first. Done correctly it will never leak.
That said, I would stick a plug in them and simply run a aftermarket trans cooler and be done with it.

[grivera]

I’m committed for the moment as the trans lines are brand new. If I can find 1/4 NPT (male) to 1/2 x 20 inverted flare (female) I will use teflon tape and put those in. Hard to find though at a reasonable price.

[grivera]

Should I seal the NPT threads with Teflon tape or RTV?

[HWYSTR455]

Here's the part number for the radiator fitting, it's an Aeroquip steel 5/16 flare to AN -6 one:

https://www.amazon.com/Aeroquip-FCM2.../dp/B000CIHY8G

Those threads don't get teflon tape or anything, the flare is what seals it. The problem is, and I've been down this road a lot, the OE line size is 5/16, and the flare matches the line size. When you over tighten an incorrect size one or even the correct size one, it's toast. I haven't found anything that will fix that without having a new fitting brazed in there, since it's a brass radiator.

It's not an NTP thread on the radiator, cooler lines are a straight cut thread pitch. That too is another potential reason for leaking in the first place.

It's cheaper to buy a Champion aluminum radiator than it is to have it fixed, they are never really 'right' after a repair like that, and it will cost half or more of the cost of the replacement aluminum one. You also run the risk of the radiator core to tank failure.

Aftermarket aluminum ones are in the $165-$250 range, depending on what you get.

What lines did you get?


.

[HWYSTR455]

Here's one for $145:

https://www.amazon.com/dp/B09L4QBLT6...kZXRhaWwy&th=1

I think the 1st gens have a different core support for the 4 core radiators, so you might be better off using a 3 or many 2 core with wider tubes. Measure.


.

[grivera]

Thanks Mike - I bought factory replacement lines from Inline Tube. I know the threads were ruined by the prior owner installing the NPT fittings- total jackass move on his part. I also realize the line fittings aren’t installed with teflon tape but that’s not what we’re dealing with here since the threads are already ruined. Since that is the case, my attempt will be using 1/4 male NPT to female 1/2” inverted flare adapter. If the NPT threads at the cooler fitting don’t seal with teflon tape, then I’ll have to decide between a new radiator and an auxiliary trans cooler.

[HWYSTR455]

The problem with NTP fittings is they taper down, which makes less thread making contact. Like I've said, I've been here before, and I never was able to get them sealed up. You might get lucky, but I seriously doubt it. Maybe if you start with a new NTP one, but by the looks of the radiator side threads, I just don't think it will happen.

I know some aren't on board with my way of thinking when it comes to bypassing the radiator cooler and using a standalone only cooler but will say it anyway. The fluid needs to be warmed up if you ever plan on driving it in anything but summer.

Most standalone coolers are only meant to be an addition to the radiator cooler, and many won't cool enough by themselves. Before any challenge that statement, have temp readings in your response, and not just for a one time reading, thru the seasons.


.

[b-man]

Buy a new radiator and be done with it.

You’ll be happier in the long run with a better aluminum radiator anyway.

https://www.coldcaseradiators.com/pr...tor?sku=CHC11A

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