Heater core question

[killj0y]

So is there a valve or something that allows water to enter the core? As in is there always water running through the heater core?

 

[JC 97]

Yes,there is a heat control valve.Your dashboard hot/cold switch is what controls the flow of water along w/vacuum.All the way hot,valve is open,All the way cold,valve is closed.

 

[killj0y]

Yea but I've noticed my truck is fine but when I turn on the heater it doesn't blow hot. Then it will overheat due to loss of coolant. But only after trying the heater. It has done it twice so I'm pretty sure that's the only change, since otherwise coolant level stays the same. I also don't find any puddles under the truck, or pressure at the cap...

 

[Brandon Nootenboom]

So if you keep the heat turned off you can drive the truck with no problem but there is still no pressure on the radiator cap?

 

[killj0y]

Turned out to be my heater control valve was rotted out and shooting out coolant. Replaced it, but it looks like most of the vacuum hoses around that area are rotted out. any idea where to her tiny vacuum house to replace them? The ac wants to run even though the heate is on, the compressor clicks on and off and it only blows heat a while AFTER the engine warms up...seems like a lack of vacuum. I replaced the valve and rotted out tip....any ideas to make it more efficient. It seems like it will only heat at speed...where it used to work anytime even when NOT wanted lol.

 

[Brandon Nootenboom]

I had some tiny plastic vacuum lines break on my Ranger and I took the piece that broke to a NAPA and they matched me up with a rubber hose with the same inner diameter, I just slipped it over the existing little piece of the plastic line and it worked like a dream. If they're rubber lines you can get new rubber line in bulk then cut it to the size(s) ya need. Then ya can get somethin like airhose connectors to connect them. Any parts store should have everything ya need