For those of you who have Ace Hardware in your town, I bought the brass fittings needed for a TB coolant bypass for about $6, including two clamps. One is a 3/8 hose nipple with male pipe threads on the other end, and the other is a 5/8 hose nipple with female pipe threads on the other end (The pipe thread diameter on both fittings is obviously the same size). Screw them together, and you've got your adapter for cheap. I spent the weekend prowling around O'reilly, Auto Zone, Home Depot, and Lowe's hardware, and couldn't find a thing, so maybe this will help someone.

 

If I were you, I wouldn't bother by-passing the throttle body coolant. It's no "biggie". I wrote a TECH TIP on the subject. If you must use your new hardware, please drain about a gallon of coolant into a clean receptacle, so that it can be reused, and prevent coolant from escaping from the hoses and nipples onto your opti. Pack rags around the hose ends and nipples to ensure there is no spillage. If you want to clean-up the engine compartment, replace the T fittings with in-line, and you can remove two hoses.

 

Thanks for the additional info. By the way, if anyone wants the actual part numbers for the brass fittings, just to make things easier when you go into Ace, post a message here. I've got 'em at my house, or I'd post the part numbers now.

 

On a 96 you don't need the fittings. Just take the line that fits to the driver side of the throttle body and hook it direct to the steam tube line that the short elbow hose that hooks to the passenger side of the throttle body is connected to. That's all I needed to do on my '95. Make sure to stuff as many rags around the opti area as possible to catch coolant spillage. Also, might have to use pliers to pull old tstat out-- mine oem stat was jammed in there pretty good.

 

Lone Ranger-

I'm not sure I'm following. Are you saying to connect the two rubber hoses together? If so, and I'm supposed to shove the smaller one into the larger one, how do you keep them from collapsing when you clamp them down? I assume they're both under pressure. Did I misunderstand your post?

 

If you examine the way the coolant is routed into the throttle body you can see that it is flowing from the metal steam tube that comes out of the back of the head on the passenger side cylinders, this tube runs along top of the head where it connects to the small rubber elbow line that routes the coolant into the tb, the coolant then flows out of the tb into the larger hose on the driver side and ultimately back into the cooling system. So instead of going through the rig-a-ma-roe of attaching a new rubber hose to the steam tube where the elbow hose was and then connecting that new hose to the hose off the driver side of the tb via a brass union fitting, just remove the elbow hose off the passenger side of tb and discard it. I had to cut my elbow fitting off it was bonded on pretty tight. Then remove the larger coolant hose form the driver side of the tb and route to the steam tube where the elbow hose WAS. Then slip it on and clamp it down. Done. Although it looks like the larger hose it too big for the steam tube to fit snuggly enough, it does. I even reused the spring tension clamp that was already on the driver side hose-- clamped it directly over the humped area of the steam tube fitting. No leaks.

This is the thread from back when I was about to do the mod, where some forum gurus turned me onto the direct connect method where you don't need the brass fitting etc;
http://forums.corvetteforum.com/zerothread?id=340063

:cheers:


[Modified by Lone Ranger, 4:57 PM 9/23/2002]

 

I know GM designed this for cold weather applications, but I'm not sure what their definition of cold weather is. I'm thinking of using a bypass valve where I could bypass the coolant in the spring, summer, and fall. Then, with the flip of the valve use the coolant running through TB in the winter.