Heater hose alterations
Thread Starter
Instructor
Joined: Mar 2010
Posts: 145
Likes: 13
From: Tampa, fl
Heater hose alterations
Ok Forum family I need some help. I need to know what these do and if I need them.
I am now going threw my engine bay and replacing anything that needs it. Today I decided to replace the heater hoses and came across this hot water shut off valve and separate heater control valve. The problem I'm having is that I can't find anything that shows these being used on a 1977.
Can anyone shed some light on these being used on a 1977 with A/C.
[IMG]
[/IMG]
I am now going threw my engine bay and replacing anything that needs it. Today I decided to replace the heater hoses and came across this hot water shut off valve and separate heater control valve. The problem I'm having is that I can't find anything that shows these being used on a 1977.
Can anyone shed some light on these being used on a 1977 with A/C.
[IMG]
[/IMG]
Last edited by newvetman; Nov 23, 2013 at 11:04 PM.
Safety Car
Joined: Nov 2001
Posts: 4,166
Likes: 2
From: Las Vegas NV
The one on the left of your pic is 100% aftermarket / non stock. I would guess that the one on the right may have been stock but failed so the other was installed. Although it really doesn't look like a factory installation. Those with an original engine bay will chime in I'm sure.
Given the amount of heat radiated into the cockpit of our cars, the manual valve is a very common addition to stop the flow of coolant into the heater core. Thus eliminating a source of heat during the summer months.
Given the amount of heat radiated into the cockpit of our cars, the manual valve is a very common addition to stop the flow of coolant into the heater core. Thus eliminating a source of heat during the summer months.
Team Owner
Joined: Jun 2000
Posts: 38,923
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From: Southbound
Cruise-In II Veteran
Factory air cars for most model years had a hot water shut off valve in one of the heater hoses. Part of your old original is still there (to the right; still has the factory Witteck clamp on the hose).
You will need a replacement. The AIM shows where it mounts. A small vacuum hose from the HVAC controls runs to it.
You will need a replacement. The AIM shows where it mounts. A small vacuum hose from the HVAC controls runs to it.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
The valve on the left was added by someone. The one on the right is stock and looks like the one in my 77.
Problem with it is that it only shuts off water supply when A/C is selected to max cold. All other cooling modes the hot water still circulates through the heater core to mix with cold air in the evaporator to create selected level of cool air.
So the passenger will experience more heat than the driver due to the location of the heater core. This is why the shut off valve is often added to shut off the heater core flow to keep the cabin cooler on the passenger side.
Problem with it is that it only shuts off water supply when A/C is selected to max cold. All other cooling modes the hot water still circulates through the heater core to mix with cold air in the evaporator to create selected level of cool air.
So the passenger will experience more heat than the driver due to the location of the heater core. This is why the shut off valve is often added to shut off the heater core flow to keep the cabin cooler on the passenger side.
Thread Starter
Instructor
Joined: Mar 2010
Posts: 145
Likes: 13
From: Tampa, fl
Ok fellas that helps me understand why it was there.
My next question is do I need both of them. The
Car came from New Orleans where shuting off the
Heat in the summer would be very desireable but
I now live in the San Francisco Bay Area where
The temperature is more mild and you may need
Heat in the summer
My next question is do I need both of them. The
Car came from New Orleans where shuting off the
Heat in the summer would be very desireable but
I now live in the San Francisco Bay Area where
The temperature is more mild and you may need
Heat in the summer
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
The best compromise for moderate temps I have found is to have a shut off valve on one of the two heater hoses. This way the heat is still available to be mixed with the cold air but is not as oppressive because the water is not flowing through the heater core so the core is cooler than it would otherwise be.
I have two shut off valves in addition to the factory one. On really hot days I shut both valves to isolate the heater core completely from the engine cooling system.
I have two shut off valves in addition to the factory one. On really hot days I shut both valves to isolate the heater core completely from the engine cooling system.
2026 Loser of the Year
Joined: Sep 2013
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From: New Or-leens Loo-z-anna
Down south, I installed a vacuum shut-off on the inlet and the outlet hoses to keep heat out of the cabin (that keeps me from having to go under the hood every time the weather changes.)
I never realized that older vehicles used heater air to regulate A/C temperatures....
Thanks for the info.
I never realized that older vehicles used heater air to regulate A/C temperatures....
Thanks for the info.
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2026 Loser of the Year
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From: New Or-leens Loo-z-anna
OOOOOOOOOOOO-K.........but when you're halfway across town with the heater on hot'n'high.......and you're still shivering........
(Just picking.....I used manual valves for years)
(Just picking.....I used manual valves for years)
Thread Starter
Instructor
Joined: Mar 2010
Posts: 145
Likes: 13
From: Tampa, fl
doorgunner I was am understanding that the manual valve is just giving you more control over the heat getting into the core during warm weather. Are you saying you prefer the stock vacuum valve and why.
Last edited by newvetman; Nov 24, 2013 at 11:55 PM.
Le Mans Master
Joined: Mar 2008
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From: Oxford MA-----You just lost the game!!!!
It's not like you're going to be turning the valve on and off every time you want heat. You turn it off at the beginning of the summer, and back on at the end of the summer. Unless you live in New England, like me, then you might turn it on and off half-a-dozen times a year. Not a big deal if you're the kind of guy who likes to open the hood once in awhile, anyway. I've never been out to San Francisco, but Mark Twain said "The coldest winter I ever spent was the summer I spent in San Francisco."
Scott
Scott
Last edited by scottyp99; Nov 24, 2013 at 09:34 PM.
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From: New Or-leens Loo-z-anna
In 50 years of winters---that's a couple hundred hood raises! (It took me about 40 open hoods and a couple times of forgetting to open the valves during cold-snaps to decide to go with two stock heater switch-operated valves which activate when the heater is operated/de-activate and keep the hot coolant out of the heater core when the heater is not used)
For those who live in climates with distinct seasons---Manual On/off valves would be a great idea!
Last edited by doorgunner; Nov 25, 2013 at 08:30 AM.
Le Mans Master
Joined: Apr 2011
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From: Hermosa
The OP will want the heater near the bay for sure on cool evenings. I spent many a night at the Oakland airport which is located on the bay and it is quite cool at night.
But on the east side and farther inland it can easily get over 100* so he will also want that A/C on max then. He'll also want highway gears to keep up with the rest of the crazy drivers in that area the go 90 MPH+ in the 65 MPH speed limit interstates.
But on the east side and farther inland it can easily get over 100* so he will also want that A/C on max then. He'll also want highway gears to keep up with the rest of the crazy drivers in that area the go 90 MPH+ in the 65 MPH speed limit interstates.
Racer
Joined: Aug 2005
Posts: 456
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From: Forty Fort PA
I use a vacuum actuated valve like the original but I added a vacuum valve like the one used on the headlight system. I placed the valve beside the headlight one just at the bottom edge of the inst panel. Gives me positive shut off and easy selection.
langg
langg
Le Mans Master
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From: Hermosa
Thread Starter
Instructor
Joined: Mar 2010
Posts: 145
Likes: 13
From: Tampa, fl
I could see that
It's just a matter of personal choice---I live down south where during the "winter" the temperature might vary 40* every week for 5 months.
In 50 years of winters---that's a couple hundred hood raises! (It took me about 40 open hoods and a couple times of forgetting to open the valves during cold-snaps to decide to go with two stock heater switch-operated valves which activate when the heater is operated/de-activate and keep the hot coolant out of the heater core when the heater is not used)
For those who live in climates with distinct seasons---Manual On/off valves would be a great idea!
In 50 years of winters---that's a couple hundred hood raises! (It took me about 40 open hoods and a couple times of forgetting to open the valves during cold-snaps to decide to go with two stock heater switch-operated valves which activate when the heater is operated/de-activate and keep the hot coolant out of the heater core when the heater is not used)
For those who live in climates with distinct seasons---Manual On/off valves would be a great idea!
Drifting
Joined: Mar 2011
Posts: 1,886
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Yep. Did the same thing meself, years ago.