Topic: INSTALLING A VALVE ON THE HEATER HOSES
in Forum: C3 Cooling and Heating Systems
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I would like to ask a couple of questions on this to get good opinions. I replaced my stock vave and and replaced the little vacum shutoff valve behind the passenger dash and adjusted it . I know mine is working properly.
1. If the valve is shuting off the one line to the heater core, will heat still be present at the heater core with the other line open?
2. If it still would be present would it not be a good idea to place another vacum valve on the other line so both lines are shutoff?you would be able to place a tee for the vacum line and control both valves.
3. mine is a 77 are other years harder to get working properly?
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anybody have the part numbers for both valves from napa
you can put a standard inline vacuum control heater valve in the input side of the heater core hose...but first check to see if you have vacuum to the valve when the heater is turned on...or no vacuum when the heater is turned on. There are two types of vacuum control valves one is called normally closed and the other normally open. If there is vacuum present when the heater is turned to hot then you will need the normally closed valve...if not you need the normally open valve...the valve should be inlet and outlet size for the 5/8" hoses. Hope this helps
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Cramerton, NC - USA
Joined: 8/22/2006
Posts: 1094
Vette(s): black 1982 coupe slate gray interior, 350 crossfire, 1985 fuel pump, Steeroids R&P conversion
Part numbers for the valves at NAPA are 3/4 inch 660-1413
5/8 inch 660-1414
I went to auto zone ,and the guy there couldn't find the part numbers in his computer. I'll try advance auto next.

Lemon Grove, CA - USA
Joined: 10/17/2007
Posts: 2041
Vette(s): 1982 C3 Collectors Edition 44000 miles, sat in the sun most of its life, My wife purchased it for me for Father's Day in 2007 from her girlfriend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.
ACPLUS John
Do you have any part numbers or sources? Can someone provide the amount of vaccum we should be getting? THis seems like a great way to not have to worry about turning it on or off manually.
[QUOTE=Tuxblacray]Jim G had some great information on this but it was long ago I am still searching for it. I believe he shot photo's of it as well. Maybe he will see this and post up.
Or..... ya'll could PM him......
For now this thread on HEAT should give ya what you need......[/QUOTE]
I'd have to go dig for the pics...or take some new ones. I have NAPA valves on both lines.
Someone needs to wake me up when a post like this comes up. Been busy with the honey do list since I got back...
Or..... ya'll could PM him......

For now this thread on HEAT should give ya what you need......[/QUOTE]
I'd have to go dig for the pics...or take some new ones. I have NAPA valves on both lines.
Someone needs to wake me up when a post like this comes up. Been busy with the honey do list since I got back...
Lifetime Member #73
The Money Pit.... and my niece
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[QUOTE=Tb2k82CE]ACPLUS John
Do you have any part numbers or sources? Can someone provide the amount of vaccum we should be getting? THis seems like a great way to not have to worry about turning it on or off manually.
[/QUOTE]
On the '82 the shut off valve closes when you turn the AC on. I don't know about the other years. That does not help when your cruising with the tops off and your feet are roasting. The best thing is to put both valves in.
Just one does not help because the heat migrates up the water in the open hose. You only need to close them in the spring and then open them in the fall, not much trouble at all.
Dave
Lifetime Member #116
Dave's '82
thanks for the part number, i also went to autozone and they had no idea what I was talking about, I also tried a local parts store with no luck
in Forum: C3 Cooling and Heating Systems
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