Reyesun

The vehicle is a 1995 F150 5.0. On the top of the radiator to the right rear (facing car) there is a 1/4" nipple. The previous owner had this fitting capped-off using a rubber hose secured by a hose clamp. It didn't leak initially but now it's leaking. My question is: what is the purpose of this nipple? I have read that it's part of the coolant system but can't find diagrams to confirm. I would greatly appreciate any information regarding this part and it's actual purpose. Can this be routed to the overflow tank which is approximately 7" to the right of this nipple?

Steve83

The overflow nipple is at the same level as the cap; if there's a nipple below that, it's NOT for overflow - it's for the throttle-body coolant return line specific to the E4OD transmission, as this diagram's inset shows:


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If you want more help, fill in your signature and post pics, as this caption explains:


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gw204

What he said. Mine is capped off with a piece of 3/8 hose that has a stainless bolt clamped in the end (was like that when I bought it). It's functional, but it's super ugly.

I'm currently looking for a more appropriate push on cap. Don't be fooled by the vacuum caps you find in stores. They aren't a long term solution.

I have an inquiry into McMaster-Carr to see if they have anything that can withstand the temps, pressures and chemicals in a cooling system. Will post what they respond with.

Something like this would probably be a great solution as well:

Heliguy93

have you found a good press on cap? my 95 just started leaking today, i was able to duct tape it to get me home but i doubt thats a permanent fix.

raski

I doubt you will find a reinforced press on cap that will withstand the heat and 16 pounds of pressure behind it. The piece of reinforced hose, plugged with a bolt and a clamped on both ends is the best long term solution.