Cooling Line question

[CarlC]

-5 is few and far between since it is used only for oxygen systems in aircraft. Since it is a dedicated size it can't be mistakenly mixed with something else during assembly.

There are adapters available to use -6 in GM transmission cooler lines, which is what is needed since all AN hose end fittings neck down much smaller than the tube/hose size they are fitted to. For example, a -6 standard hose end (red/blue) will neck down to about 0.250". A -5 would be even smaller.