'93 F150 302. Been chasing a coolant leak for some time. Only seems to leak after driving about 10 or so miles. Finally spotted anti freeze on the fitting that comes out of the bottom of the throttle body. Can this be fixed?? Seems to be leaking where the fitting either screws or is pressed into the body(don't know which). Before I tear into it I thought I better seek some advise!! Thanks 'Mo

 

That's a fairly common problem, but I had a hell of a time getting my throttle body to stop leaking. First it started leaking from the freeze plug type thing on the side, so I plugged that. Then the top hard line began leaking, so I bypassed the throttle body all together with a piece of fuel line I had laying around the garage. That worked great for about 6 months until the fitting on the tree where it goes into the block started leaking. After that I said the hell with it and found a metal plug with the same threads for the tree and a vacuum cap for the hose the coolant was coming from. Haven't had a leak since.

Anyway, if you're looking for a quick fix just bypass with with about a foot of fuel line. If you're looking for something more permanent, I suggest finding plugs for where the coolant comes from and where it goes.

 

Do you know if those water fittings are pressed in or screwed in??? Just how important is coolant flow to the throttle body?? Could freezing occur in the body without the hot water under certian atmospheric conditions? I'de rather not bypass it if possible. Priced new TB and had to take a nitro pill!!!!!

 

Pressed.

It's only there to prevent the TB from icing over in very cold climates. I live in Florida so it's not important at all, but I suppose if you live somewhere where it's below freezing a lot then you could have some potential problems. I guess you would have to talk to someone who lives in a cooler climate than I do.

And yes, new TB's are quite expensive. I considered buying a BBK one a while back when my mechanic was convinced I needed a new one (turned out to be a bad TPS even though it was brand new).

 

I dunno... It gets pretty cold in Hernando.




You can bypass that safely during the summer. But if you make long drives in winter, there's a SLIGHT risk of ice locking the throttle open. When you have a long weekend to mess with it, pull the TB off, clean it, and load that leak up with JB Weld.

But the source of the problem is INfrequent coolant changes. Regardless of mileage, coolant goes bad over time. It must be flushed & refilled at MOST every couple of years. Don't ever use "long-life" coolant - it doesn't last as long. And don't use premix - it's a rip-off.

 

I bypassed mine 2 years ago, and the PA winters have not caused me any problems. Also, I don't know if it's true, but I was told that the primary purpose of the coolant flow through the TB was for emissions purposes, as the air entering the manifold will be warmer if the TB is heated. Anyone know if this theory holds water?

 

Thanks steve, Your right, it does get pretty cold in hernando!!! Seems like with the high humidity we get here with cold wet air you have a recipe for icing!!! I'm gonna tear into it this morning. Seems like JB Weld is as handy as duct tape!!! 'Mo