3/8"...but why would you want to go to all that trouble. Just plug the lines and go.

 

I want to be able to easily hook it back up in the winter. I'm thinking I can just flip the two lines, and flip them back in the winter. That way the hose will go from the top to the bottom of the TB, and the other hose will just go from the intake back to the return heater hose line.

Do these trucks have a heater core shut off valve with ac???

 

Thats what I was going to do 3 summers ago, but 2 winters ago i reliezed that I didnt need to swap them back.. Here in MI it only get to about 10 on avg, max -10 with a bad snow storm which is rare.

Just connect the heater line to the coolant tee near the distributer and then plug the 2 TB inputs with vinal (I cant spell that right for some reason ) or rubber vacuum plugs.

But anywho, plug those and your set.

ADam

 

I have been sitting on this idea since I rebuild my motor, after reading this, I think I'm going to try it too.

 

I live in CT and spent two years in Kittery, ME with my coolant lines cut and plugged. No problem at any time with sticking throttle plates (which is why they were designed). Unless you live in Alaska...cut em and plug em. I cut mine off at the radiator and the intake, no more coolant lines cluttering up the engine compartment.
Check gallery for photos, more/better photos on website.

Hope this helps.

 

it's these hoses, right? http://webpages.charter.net/lrrouth/pics/tbcool/
I tried following the bottom one to see where it went, and I saw a sensor attached, what is that?

 

thats them alright

 

Yup, that's the pesky varmits. One line goes to the radiator, and the other goes to a small tree on the manifold. The coolant temp sensor is what you are seeing at the manifold, it shares the tree with the TB coolant line. I disconnected the coolant lines at the tree, radiator, and of course, the throttle body. Threw the whole assembly in the trash. Took fuel line, cut off two pieces about 1.5" each, put a plug in the end and clamped them. Put the plugged hose pieces on at the radiator and manifold tree with hose clamps. Job done, works like a champ, never a single problem.
Check gallery for photos under throttle body upgrade, more/better photos on website.

Hope this helps.