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Mobious5

Heater Control Valve (auto air)

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ommm my heat dose not work and i think its because my auto air heater control valve has had it and is no longer working. For starters my air condition comes on only when it wants to. I've done everything to try and figure that one out and still nothing. But my defrost still works and blows air pretty strong.... just cold air.

 

When i squeeze the hoes into the valve while reving up, i can feel pressure building but not on the return hose. So i guess the heater core could be plugged but i'll start with control valve. Judging by the white and green corrosion all over it, i'll start there.

 

 

1229091003b.jpg

 

1229091003b.jpg

 

so what i want to no is, am i on the right track as far as replacing this first? And instead of using the auto air valve, cant i just rig up something like a manual valve that i can just twist the valve open and let the hot fluid through???? this would be so much easier because im afraid there might be a problem with me a/c control unit thats keeping the valve from opening.

 

Thanks!!!!!

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In most cases, it turns out to be a vacuum leak that causes these issues. Unless you are 100% certain none of the small vacuum hoses are cracked/loose/missing, I'd start there. It may turn out to be that simple to fix.... :2thumbs:

 

+1 on this

 

You do have the option of switching to a non auto air system if the control unit is bad. Those valves are allways setting in corrosion filled water and after 20 or 30 yrs they do go bad. good luck

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i just went through the same problems w/ my 77 w/ a-c ..

 

here is what i used, along w/ a cable operated valve that was a push to close.

 

http://www.4s.com/Online%20Catalogs-eCatalog/Content.aspx

 

part # 74614

 

i am pleased to say that my system works GREAT now. and no leaky. :mrgreen:

 

 

yea i found a sight where i can order this 4 seasons part. Thanks a lot! saves A LOT of money lol !

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The cheapest thing to do is replace all your vaccuum lines associated with the heater. You will probably stumble across on ehtat is cracked that you didn't see before. About 5$ worht of hose is pretty cheap and easy. I am speaking from experience:mrgreen:

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so this is what happened....

 

0105001640.jpg

 

almost as soon as i touched it lol. I guess it snapped due to the corrosion and still water.

 

but this is what i came up with instead of buying at new one, because i am a poor college freshmen.

 

0104001557.jpg

 

Shizz-zam. I took a couple feet of heater hose and ran it FROM the head DIRECTLY into the heater core inlet, bypassing the broken valve. Then i added in a manuel shut off valve in between.

 

Now this is all working well in my mind. This is where is bites me.

 

I open the valve, let the car heat up, everythings good, I turn on the blower , and YES! warm air filling my car YES!

 

I hop out look under the hood and a few minutes later.... miss getting sprayed in the face by hot water blowing out of the coolant reserve!!!!!!!

so i hurried and closed the valve, the spray stopped and so did the hot air...

 

Help. what would cause the water to blow back like that?

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Yea the heater hose coming from the head bends towards the front of the car, under the injector fan then loops back around, valve, then trough the fire wall.

 

Is there another valve in the return line somewhere? I know there's a coolant temp sensor.

I think the core might be plugged.

 

thanks

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