deleted

[Alex Meanberg]

deleted

 

[Exproblems]

I'm tracking down a coolant leak. What the hell is this thing, exactly, and how would I go about fixing it?

]

Unless I'm mistaken, the device in your pic would be the "heater control valve", which is vacuum operated by that grey colored vacuum line connected to it. It's connected inline with your heat core hoses that run up from the t-stat housing and/or water pump and run into the firewall and into the heater core under your dashboard. Do a search on "heater control valves" for your year Explorer with engine size in this forum and you'll pull up past posts on that topic and repairs for it. It's not a hard fix, but you'll have to drain some coolant out of the system to install a new valve and probably replace some heater core hoses as well.

 

[BigRondo]

I agree with Exproblems. Heater control valve.

I have the shop manuals and can forward the replacement procedure upon request.

Good luck getting it sorted.

Please keep us posted as feedback helps others reading this post looking for a fix to the same or similar issue!