Trans cooler fittings:

[vandelay industries]

What is the exact size, and type, fitting that screws into the trans cooler in the radiator?


Essentially, what i'm trying to do is the flush thing. But my radiator does not have the nipples that protrude, so i can't put a hose over it. So, i need a barb fitting.

 

[diesel4me]

"Most" GM's use a 5/16" steel line that screws directly into the radiator--those have a 1/2" x 20 male thread with an inverted flare..
There are exceptions...

Easiest and cheapest place to get barb fittings that are correct is at a salvage yard--however,most GM's used no adapters or barb fittings,the steel line goes right into the bung on the radiator..
I'd just get a short hunk of 5/16" brake tubing with the flare nut fitting and use rubber hose on it to flush the cooler out..

 

[vandelay industries]

"Most" GM's use a 5/16" steel line that screws directly into the radiator--those have a 1/2" x 20 male thread with an inverted flare..
There are exceptions...

Easiest and cheapest place to get barb fittings that are correct is at a salvage yard--however,most GM's used no adapters or barb fittings,the steel line goes right into the bung on the radiator..
I'd just get a short hunk of 5/16" brake tubing with the flare nut fitting and use rubber hose on it to flush the cooler out..

That's probably the best route----just cut a little off from the radiator and slip a hose over it....

 

[diesel4me]

Yeah,and you can use a 5/16" compression union to join the tube back together again,unless your replacing it...

On some of my "antique" GM's the radiator tank looks corroded enough where the cooler lines screw in,to rip the bung right out if I try to unscrew them--so if the line isn't rusted badly,I cut it off a few inches away,and splice on a new length of tubing using a compression union,or a flare union..
I like using unions a few inches away from the fittings on the transmission too,because getting at them with a wrench is a real nutbuster,so is trying to get a new line to thread into them,and get it bent just right to allow it to thread in...