what to seal tranny line fitting threads with?

[John6185]

If I'm reading this correctly, you've put a radiator in w/o transmission cooler fittings. Me, I'd go to Autozone or another auto parts store and buy a transmission cooler that would fit on front of the radiator and hook it up to the lines running from the transmission. The transmission heats up a lot and needs to expend the heat and the aux cooler does this. You want your transmission to last a long time.

 

[sh00ter]

Use this and thank me later.
http://www.jegs.com/i/Loctite/198/3...oIqF59w1QzS84HOE8bsUBUwEfhxbSJryuYxoCo0Hw_wcB

thx I will take a look

Teflon tape is a no go on that fitting. What you need is either a boss oring (face seal and other types will most likely leak) or a sealing washer. Don't reuse the old washer, it won't seal properly 80% of the time.

I was not aware of any oring on the factory fitting, but this is a NEW radiator and the fittings come pre-installed in the new radiator complete with a new washer. it isn't leaking from there, it leaks from the threads where the metal nut (with metal line) screws on...I'm sure it is the threads...the OWM metal line/nut was not damaged when removed. I will check to be sure there is not an o-ring but I do not belieb this type of fitting uses one where the metal nut screws onto it.

If the flare is damaged and there is enough slack, it can be reflared. If the end in the radiator is damaged, you can replace it or any radiator shop can too.

new radiator as mentioned, as for the flare, this was the OEM radiator that was removed so the lines (flare) should be in good shape still. I think I just need something to seal the threads...this is a CHINESE radiator and the fittings that were pre-installed might not quite be as good as the OEM fittings that are screwed into the old OEM radiator (non-chinese). I suspect screwing the old OEM metal lines/nuts into the new chinese fittings is why the threads don't quite seal.

 

[NightShade]

Just replaced the radiator in my 4.7l Dakota about 6 or 8 months ago and while it didn't have fittings pre installed they had o-rings on the factory lines.

It could be just what you surmise that the new included fittings are a different thread or slightly different size than the OEM and that is why they were included. Hopefully you didn't pay that much for this thing. I got mine from Sunbelt Radiator and it was honestly cheaper than anything else I could find. I can't remember if I bought direct or through Amazon but it was fast shipping and has worked great. For an 03 4.7l dakota I paid seventy bucks and I think shipping was free.