I've been looking into maybe getting one of these. What I don't really understand is the ones I am finding have rubber hoses that go to the cooler, Not lines that screw into it (like on a radiator) I thought there was so much pressure in the transmission lines, that you couldn't use rubber hoses, that and it deteriorated them?

Am I missing something somewhere, or am I wrong on the use of rubber hoses?

 

"Pressure" isn't so much the problem, as there's not usually more than 25psi or so in those; it's the heat that does them in.

Smart people take those hose nipples out and put in AN or pipe thread fittings usually; and of course avoid the ones with the permanently molded-in hose barbs.

 

Line pressure shouldn't exceed 250 psi. It normally operates lower than that. When using rubber line, make sure it says transmission line on the side of it. Tranny line is stronger and designed to handle the high heat compared to regular rubber lines.

If you ever go to a dragstrip, you'll fail tech if rubber transmission lines are not the correct type of line.

All lines should be hard line as much as possible with rubber lines used only to join components. Everyone simply uses rubber line when installing an external cooler.

 

So I'd be alright to run my hard lines to say 12-14 inches from the transmission cooler, and then rubber (atf) hose to the cooler IF I needed to?

 

That's commonly how it's done; which is not to say it's "best", only, "common". Pressure is relatively low there, as the "cold" side of it goes back to the pan via a path that lubes a bushing IIRC, and the "hot" side comes from the converter, which is fed by the waste fluid from the regulator via the TCC solenoid. Power steering return hose lasts reasonably well for that but is still a regular maintenance item. It would be better to run one that has actual fittings, for example in the style like this one here has, http://www.ebay.com/itm/TRU-COOL-MAX-LPD-47391-40-000-GVW-LOW-PRESSURE-DROP-TRANSMISSION-OIL-COOLER-/321064173710?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ac0ea808e&vxp=mtr or one like a Setrab that has AN fittings on it, so you can avoid using rubber line at all.