Part Identification

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Anbizou

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Location
NM
First Name
Jose
Truck Year
1979
Truck Model
C10
Engine Size
5.0L V8
Recently got back from Mexico and finally changed the water outlet w/ gasket and added a thermostat as well. The truck overall runs fine however the thing is you need to keep your foot on the gas pedal otherwise it will shut off and you’ll then have to turn it on again. My dad said it’s because there’s air entering some disconnected hoses for the heater to which his temporary solution was insert some screws in the hoses so there wouldn’t be much air entering. The picture below is the old water outlet. The thing on top of it is supposedly what the hoses are supposed to connect to. Any idea what it’s called, Where I can obtain, or wether that’s even the issue to begin with? Thanks!

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Anbizou

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Location
NM
First Name
Jose
Truck Year
1979
Truck Model
C10
Engine Size
5.0L V8
Picture of the new outlet along with a general view of the engine

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Ronno6

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South Mississippi
First Name
Ron
Truck Year
1984
Truck Model
C10
Engine Size
355
That is a thermal vacuum switch. It was designed to reroute vacuum to or from various devices when the engine reached a preset temperature. Generally part of the myriad of vacuum lines and devices for pollution control. May have controlled vac to EGR, exhaust dampers, distributor,air cleaner cold air dampers, or who knows what else.
I cannot advise you, but most you will see on running vehicles have been disconnected along with the other stuff in the system. Make sure you have no vacuum lines left unplugged.
 

Craig 85

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1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
The other name they are referred to is "ported vacuum" switch. Here's the link to Napa's listing for your truck if you're still running a 305. If you don't have emissions testing, I would not hook up all the unnecessary vacuum lines.

https://www.napaonline.com/en/searc...cation=true&indices=API&referer=nol-veh-conds

Auto Zone has a emissions hose diagrams. Start at Figure #32 and determine what set up you have.

https://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0900c152800aef5b
 

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