Fronzizzle

I have an aftermarket radiator with built in trans cooler, a 383 and 700R4 that was built up from a kit purchased from Dana at Pro-Built Automatics.

Everything has been installed for about a year or so. During that time, I haven't driven the car a lot (much of that time was spent finishing the engine & getting the body work done) but over the last couple of months, I've been driving it quite a bit. At least 20-25 times I've had the car on the road for 20+ minutes and up to full operating temperature. During that time, I've had zero trans fluid leaks or issues.

Yesterday, after another 20 minute drive, I pulled back into my garage and popped the hood to do some quick work. When I did, I happened to look down and see a rather large puddle of transmission fluid. I checked, it appeared to be coming from the lower cooling line that goes into the radiator. I checked it, it was maybe a little loose, I gave it another 1/4 to 1/2 turn and didn't want to go further for fear of breaking something.

I took the car for a ride this morning, pulled it back in and now the leak is worse. With the car running, I verified that the fluid is pouring out around the threads of the line.

I let the car cool, put it up on jack stands, crawled underneath and removed the line. I fully expected that the flare was broke, but the line looks intact. I checked the whole line out with my hand & a mirror and even had my wife look - not cracks can be seen. I also used a mirror to look into the radiator, it's very difficult to see but from what I can tell that looks fine, too.

So...not sure where to go from here. Is it possible the line or flare is really cracked and I just can't see it? Why else would it just start leaking - bad - all of a sudden? I am somewhat concerned that something happened in the transmission that caused an increase in pressure and now that's why it's leaking. I don't even know if this is possible, just a thought. The fluid looks brand new still, it's just red with no hint of burning or debris. And, the transmission is acting the exact same, no change in the way it's shifting, no noise, etc.

I was going to try and put it back together and see what's going on, but I'm a bit concerned as even if it doesn't leak now, it may leak in the future and I've got some cruises and car shows coming up. Any advice?

Fronzizzle

I pulled the line apart yesterday, the flare itself looks good. When I went to put it back together, though, I found that the nut just won't tighten. It gets to a point where you think it's tight, but as soon as you start the car it leaks and then when I got and check it, it's loose again. I assume the threads in the radiator fitting blew out somehow.