HDFLH67

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!

SanDiegoPaul

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

Smokehouse69

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.

LiveandLetDrive

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]

Paul L

I can confirm that non-A/C cars have the valve. It prevents hot coolant from passing through the heater core in warmer weather.

74-Roadster

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.

Bobchad

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.

HDFLH67

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!

HDFLH67

Thanks for your help! Is there any way to test these valves?

jetech

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.

Paul L

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]

Bobchad

First test for vacuum at the line. If you have it and the valve is original, spend the $20 and get a new one.