Technical tranny cooling lines

Got a 2.3 pinto with a C3 behind it in my 27 roadster, test driving it yesterday, after around a couple miles or so, one of the lines blew partially off right at the cooler on one of my custom made lines. Of course, it's right behind the grille shell well out of reach and a tear down is necessary, oil everywhere, huge wipedown gonna happen today. Anyway, this has never happened to me in many years of building, lines are made with a partial flare, proper transmission hose used, the proper size, really a surprise to me. How much pressure do these lines carry? I thought it was around fifteen pounds or so, but now I'm not so sure. The pressure line to the cooler enters the bottom of the cooler and the return leaves the top, mounted in front of the rad on it's side, three row hayden cooler. Pics won't help, it's stuffed in behind a custom grille shell, you can barely see it never mind take pics.

 

I've always done a single flair on the metal line and slipped it in the rubber hose a few inches. Then a hose clamp right behnd the flair and another near the end of the metal line. Been doing it this way since the 60's. with no porblems.
Maybe your clamp just wasn't tight.

 

Loose clamp, how much pressure is in these lines?

 

TCI chart

 

I may be wrong, but I think that TCI chart is line pressure. Which isn't cooler line pressure.

I've always thought cooler lines had around 20 psi but I am not sure where I got that idea.

 

I think you might be right, I'll retract that earlier statement

 

Make sure to use this. Handles the pressure and higher temps. Double clamp!

 

By "partial" flare I am assuming that you used the die in the double flare tool to make a bulb at the end of the tube to slip a hose over. I've never had a problem with that as long as I used the proper type and size of hose for the fluid I was working with.

I'd have to ask if the hose and end were different sizes, if the clamp was not tight or tight but not in the right spot or if it wasn't the correct hose for trans fluid.

 

No.... my stupidity, as usual, yes that's how the steel line is made, but in my haste to get it running, (I'll get that later), I didn't push the hose onto the steel line far enough, or tighten the clamp enough. Of course, never thought to recheck it. Proper hose, proper lines, just the dummy at the controls, I was just blown away by the amount of oil it pumped out over the course of a city block, trying to get it back to the shop, which I did. Even though it was a partial leak, it's blown oil all over the engine and inside the hood and side panels, made quite the mess. That's why I'm curious what kind of pressure the cooling lines run, anyone know?

 

DO NOT USE FUEL LINE

 

Most Ford 3 speed trans run 20 - 45 psi in the cooler system. Please be careful with cooler lines. They often run near , over , around the exhaust system. Trans oil can flash over to a fire from exhaust tube temps

 

Thanks for the info.

 

Cooler line pressure is convertor out pressure. when it returns from the cooler and enters the transmission it becomes lube pressure. Condition of convertor may change that pressure, and failure of lube pressure regulator also. Install pressure guage and read lube pressure. Lube pressure varies from trans to trans.

 

I don't always use clamps,

but when I do... they
are for fuel injection.

 

I also use a short piece of hose at the radiator connection.

 

Please educate me. Why not?

 

Thanks. You found the problem and passed it on!

 

Transmission fluid brakes down the rubber in fuel lines

 

Interesting, I've always just run fuel line. Is this something that I should switch out?

 

Thanks, I thought you were talking about steel line. No rubber not good, made that mess already!

 

I would switch it out. I've seen others use fuel line and it comes apart after some time.

 

Cool, the next question is, Will the parts store peeps know what I'm talking about?

 

Just get steel brake line in the correct diameter and bend away. Put double flares and fittings just like brake lines.