Heater shutoff valve
Thread Starter
Racer
Joined: Nov 2005
Posts: 339
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From: San Jose CA
Heater shutoff valve
I have an '82 vette. I want to install a shutoff valve on my heater hose. What size ball valve should I buy? Do I install the valve on the hose that goes from the rear of the engine (near distributor) to the firewall? Thanks.
Race Director
Joined: May 2006
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From: Dayton, Ohio
Originally Posted by Marcusk408
I have an '82 vette. I want to install a shutoff valve on my heater hose. What size ball valve should I buy? Do I install the valve on the hose that goes from the rear of the engine (near distributor) to the firewall? Thanks.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
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From: Boca Raton Florida
An 82 should have one in there already, it will be a vacume operated unit. I have not verified it yet but I was reading in here (I think from Bernie) that the factory valve only cuts off the water with max ac selected. So maybe an extra valve is a good idea. If thats the case I will be reworking the vacume circuit so that it is only open with heat selected
Race Director
Joined: May 2006
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From: Dayton, Ohio
Sixfooter - there is a vac. valve on top of heater core box inside car that is controled from the temp cable-move lever to cold and valve operates-when new it did well but when they get older the cable cant keep valve seated-I usually put a slight bend in wire part of cable so when it moves through the cable housing it has some resistance and then it will hold valve in position---the water control valve needs vacumn to shut off hot water--Max AC is a mode door thing like Recirc on other cars
Last edited by ...Roger...; Aug 4, 2006 at 08:51 AM.
Thread Starter
Racer
Joined: Nov 2005
Posts: 339
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From: San Jose CA
Ok, so I'll use a 5/8" shutoff valve for the inlet. Is there a way to test the factory vacuum valve to see if it's shutting off the flow of coolant to the heater core? I know there's vacuum at the little vacuum hose that goes to that valve but how do I know if the valve isn't stuck open internally?
Le Mans Master
Joined: Jul 2000
Posts: 6,664
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From: columbia city in
you can do a search on this forum and find alot on the heater valve .the factory valve does not turn off compleatly ,it lets some hot water come thru, even a new one will leak ,thats why so many have gone to the manual valve .
Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
A simple $2 spring clamp on hose works great-no extra connections to leak-on in the summer and off in the winter-in addition to the factory shutoff it works-the hose pops right back-why make it so complicated?
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Thread Starter
Racer
Joined: Nov 2005
Posts: 339
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From: San Jose CA
Originally Posted by dwncchs
A simple $2 spring clamp on hose works great-no extra connections to leak-on in the summer and off in the winter-in addition to the factory shutoff it works-the hose pops right back-why make it so complicated?
Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
Originally Posted by Marcusk408
Hmmm...sounds like a good idea. I won't have to cut into the hose this way. So what does the spring clamp look like? Where can I get one?
-------Put it on when hose is warm.
Last edited by ...Roger...; Aug 9, 2006 at 08:37 AM.
Team Owner
Joined: Oct 2004
Posts: 23,831
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From: Springfield MO
St. Jude Donor '07
Originally Posted by terry82
you can do a search on this forum and find alot on the heater valve .the factory valve does not turn off compleatly ,it lets some hot water come thru, even a new one will leak ,thats why so many have gone to the manual valve .
Advanced
Joined: Mar 2003
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From: calhoun city ms
Are you trying to stop hot air from entering the cabin via the continual ventilation? If this is the case go to a local NAPA or other parts store and buy the cutoff's and put in the heater hose. I put one in both heater hoses just because it gets really hot and humid here in Mississippi. Your fan will continue to blow air when all the HVAC controls are off unless you change the wiring at the fan motor. The cutoff valves can be mounted down low in the hoses so they will be out of sight when raising the hood.
Le Mans Master
Joined: Oct 2001
Posts: 6,798
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From: Pine Bluff Arkansas
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21
Rather than using a valve or two...I simply by-pass the heater(like the guy from Fl.) You can buy a plactic connector for about $5 from any parts store. Pull the hoses from both sides of the heater...install the connector(5/8 on one end and 3/4 on the other). Connect the two ends that you pulled from the heater. Your bypassed. No valves to buy and no hoses to cut. The 2 clamps you need are already there. Come winter time...take the connector out and throw it in your glove compartment for next summer. I've done it both ways....and this is the easiest for me. Larry
Thread Starter
Racer
Joined: Nov 2005
Posts: 339
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From: San Jose CA
I've installed a shutoff valve on the hose going from the rear of the manifold to the heater core (inlet?). There's no noticeable difference in the air temperature. Hmmmm...Should I install a shutoff valve on the other hose too? Seems to me like the coolant would still enter the heater core through the outlet hose unless there's a check valve or something in the outlet hose that prevents coolant from entering the heater core.
Le Mans Master
Joined: Oct 2001
Posts: 6,798
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From: Pine Bluff Arkansas
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21
Usually one valve will make a difference. You can always put another valve in or by-pass the heater completely. I would have bet that one valve should have done something, tho.
Larry
Larry