Even though it's still colder than a witches ... here, I'm thinking about keeping cool this Summer!!

I am considering adding a hot water cut-off valve on the '72 to improve cooling in the interior. Coupla questions:

(1) Any reason they didn't use these in 72? GM seemed to include them in many years before and after. Any reason not to add one on??

(2) Which hose should it go on? The one coming out of the water pump, or the one coming out of the intake manifold?

THANKS!

I don't know why they didn't have one but I put one on mine in the hose that attaches to the intake. I bought it at Autozone for $12.00. I think it said it was for a 77 Impala. Its a manual switch so if I need to open it I just open the hood and turn it on. It is made to have a cable hooked to it so if you wanted to you could rig something up.

Just put one in my 73 two weeks ago. Got a vacuum operated valve from the local junkyard ($1) you can get a new one from NAPA for $17. Connected the valve to a second headlight bypass switch I mounted in the interior. Pull the switch down and I have hot water to the heater core, push the switch up and no hot water to the core. The valves are usually for 5/8" hose. On my Corvette the hose from the water pump is 3/4" and the hose from the intake manifold is 5/8". I mounted the valve in the area between the exhaust manifold output and the radiator overflow tank.
Roger

Roger...thanks! I guess the hose size is the clue I'm looking for. Great idea on the vacuum...I was going to try to figure out which one of the existing lines would be in the right position (open or closed) at the right time... I got a valve at Carlisle last August for $2...just haven't put it in yet!

Hi Brian, I want to install the hot water cut-off valve. When I went to my local auto zone and asked for one,(or should I have asked for a hot water cut-off switch) they looked at me as if I had two heads. Would the part that I need be in the radiator section, and what is it made out of metal( brass ) or heavy gauge plastic, thanks for you help.

Tom

Mine is a manual brass screw in type which provides tight shutoff. I previously had a manual quarter turn ball valve which was leaking by fluid.

i plan on placing mine behind the passenger side gill. both heater hoses run behind it and it's easy to get to and not visiable looking under the hood.

"Hi Brian, I want to install the hot water cut-off valve. When I went to my local auto zone and asked for one,(or should I have asked for a hot water cut-off switch) they looked at me as if I had two heads. Would the part that I need be in the radiator section, and what is it made out of metal( brass ) or heavy gauge plastic, thanks for you help.

Tom "

It was listed as a heater shut-off valve. It was molded plastic with a metal bracket to attach the cable to it.

I did find this vacuum operated valve:
AC Delco Part# 155220 Heater valve
http://www.rockauto.com/ref/ACDelco/Detail.html?15-5220.jpg

|UPDATED|2/21/2004 6:23:48 PM (AZT)|/UPDATED|

Thanks Brian, I lucked out, I went to a more knowledgeable parts store and they knew exactly what I was talking about even showed me a catalog with several to choose from. I went with what most of what you guys in the forum suggested and that was the screw type oppose to the ball valve type. I put it in place of the vacuum valve that was original there. I believe that vacuum valve is for the A/C but presently mine is disconnected. Plan on replacing the compressor in the spring. I believe that the shut-off valve that I installed will serve the same purpose as the vacuum operated one when I want to use the A/C correct?

Tom

what exactly does this shut off valve do?? Does it stop coolant from going into the heater core, which in turn allows more to go to the radiator or what??