Heater Control VALVE
Thread Starter
Racer
Joined: Jan 2003
Posts: 294
Likes: 0
From: Rochester NY
Heater Control VALVE
My '69 was originally equipped with air conditioning, but that is long gone now.
There is a "heater control valve" in one of the hoses from the water pump that seems to only show on air conditioned diagrams. Can I eliminate this valve now that I am without the AC?
Thanks!
There is a "heater control valve" in one of the hoses from the water pump that seems to only show on air conditioned diagrams. Can I eliminate this valve now that I am without the AC?
Thanks!
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Re: Heater Control VALVE (HDFLH67)
When I put the motor in my car last month, I jsut put plugs in the water pump and intake manifold.
I figured there's ENOUGH!!!! heat in the car already! :lol: :yesnod: :yesnod: :yesnod: :flag
I figured there's ENOUGH!!!! heat in the car already! :lol: :yesnod: :yesnod: :yesnod: :flag
Le Mans Master
Joined: Aug 2000
Posts: 9,662
Likes: 7
From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: Heater Control VALVE (HDFLH67)
The heater control valve is a vacuum actuated valve in the heater hose to the core. It is connected to the heater/AC control system so that when the car is in the A/C mode it closes the valve so no hot water flows through the core. It also keeps the water from circulating when the heater is off.
If you elimate the valve you will have hot water going through the core at all times, even when you don't have the heater on.
This could cause some problems, with heat leaking into the cabin. I thought that all 'vettes had this valve even the non-AC cars, I guess I could be wrong.
If you elimate the valve you will have hot water going through the core at all times, even when you don't have the heater on.
This could cause some problems, with heat leaking into the cabin. I thought that all 'vettes had this valve even the non-AC cars, I guess I could be wrong.
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
Re: Heater Control VALVE (Smokehouse69)
non-AC cars had a different one, but I have no idea why they needed to be different... mine was plugged for a while, but it's nice to have heat in the winter, by summer I plan to have the vacuum hose routed so I can shut off the heat.
-Chris
[Modified by RUXperienced, 6:07 AM 2/9/2003]
-Chris
[Modified by RUXperienced, 6:07 AM 2/9/2003]
Le Mans Master
Joined: Nov 2000
Posts: 5,210
Likes: 104
From: Fort Worth TX
St. Jude Donor '06
Father & Son St. Jude Donor '09
Re: Heater Control VALVE (Smokehouse69)
Believe it or not, as I confirmed here on the forum, some of the mid 70's sharks didn't have one. My 74 never had a heater shut off valve. Others like me found a vacuum operated valve from an early shark or late model GM replacement and installed their own. If I stay with factory controls, I will install one as well. It just involves a "T" in the correct vacuum line from the controls to the valve.
Burning Brakes
Joined: Jun 2002
Posts: 792
Likes: 2
From: Norcross GA
Re: Heater Control VALVE (HDFLH67)
It appears that you need this valve but you may have another problem. If you removed the a/c system, the vacuum line may not be hooked up to anything. With no vacuum you will have hot water in the heater core whenever you drive. This is one of the causes of excessvie cabin heat in the shark. So you either need to make sure the vacuum system is working, or add a manual valve that you can close and open as you need hot air in the car. Oh yeah, even if you have vacuum to the valve you may find that it does not work very well.
Thread Starter
Racer
Joined: Jan 2003
Posts: 294
Likes: 0
From: Rochester NY
Re: Heater Control VALVE (paul79)
Thanks for the pic. I guess I need to keep it then! Is there any way to test to see if it actually works? Can you describe where yours is mounted? I can't tell from the pic. Mine is just hanging loose underneath!
Thanks again!
Thanks again!
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Racer
Joined: Sep 2002
Posts: 392
Likes: 0
From: Iowa
Re: Heater Control VALVE (HDFLH67)
The valve is vac operated to the closed position via the A/C control switch. You may be able to position the A/C control to "A/C Max or high" and check for no temp rise at the heater hose on the core side of the valve. If that doesn't work then remove the valve and apply vac and see if the valve closes. My valve is a little different (1977) and I can see the inside of the valve.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Re: Heater Control VALVE (HDFLH67)
I am working with archived pics as my car is in winter storage so bear with me.
The valve does hang free with the heater hoses.
But the hoses are secured to the inner fender liner by this bracket/clamp. The system does work very well.
[Modified by paul79, 2:59 PM 2/9/2003]
The valve does hang free with the heater hoses.
But the hoses are secured to the inner fender liner by this bracket/clamp. The system does work very well.
[Modified by paul79, 2:59 PM 2/9/2003]
