what is this part, and what's supposed to go here?

[MetalMan390]

i just bought a 05 f250 diesel, and noticed that there appears to be a vacuum line missing from this part, don't know what it does though:





anyone know what this part is and what is supposed to go there? i don't see any vacuum lines near it that are not attached to anything.

[m-chan68]

That's your heater control valve. It blocks off coolant flow to the heater core when the A/C is set to the cold setting, to improve cooling efficiency.

[chuckles]

if you are looking at the top port, that is just a vent, nothing goes there. As long as the grey line on the front is hooked up, you're fine.

[MetalMan390]

Originally Posted by chuckles

if you are looking at the top port, that is just a vent, nothing goes there. As long as the grey line on the front is hooked up, you're fine.

thanks... thought that might be the case but figured i'd ask