here's another goofy question from a noob. i read something here before about plugging the heater hose from the pump area to the core near the fire wall . this was to allow no heated water to circulate through the core, thus allowing no heated water near the air conditioner works. is there such a thing? would the water just bypass the heater hoses, etc.? i never use the heater here in south texas--it's ALWAYS hot here, and i can use every trick to help my a/c. thanks a lot .

GM used a heater control valve in one of the heater hoses going to heater core that was vac controlled so when the ac was turned on the valve would close so no hot water could pass thru the heater.

Or you could just remove the heater hoses and cap off the connections at the block or maybe pull the hoses off at the firewall and attach togehter with one of the HELP Conectors from the autoparts store thats 5/8 on one end and 3/4 on the other end.

Then you can test things out by running ac with the heater hoses unhooked and attached together and if doing that helps the ac run cooler and you dont need the heater then remove the heater hoses and then cap off the connections or install a heater cont valve in a heater hose.

Scott

my local parts house had a valve that i installed in the heater hose coming from the water pump to the heater core. it is a manual shutoff and works wonders during the hot alabama summers. about $10.

my local parts house had a valve that i installed in the heater hose coming from the water pump to the heater core. it is a manual shutoff and works wonders during the hot alabama summers. about $10.
Same here, picked up a small gate valve at hardware store, installed it. Keeps it cooler in Alabama.:yes:

I also have a water shut-off valve to the heater core on my wagon.
Bob:thumbsup:

a photo please, when someone gets time. thanks.

Our heater core went out and leaked water all over the carpet. What is the best way to replace the heater core and how hard of a job is it? This is for a 1964 Chevelle convertible with factory air. Any help will be appreciated.

Pat ,you might start another thread with your issue rather than hi-jack this one.

Jack, an easy, sneaky way to do this is to take the fittings off of the intake and water pump, braze the holes shut, or drill & tap the back side of the fittings for pipe plugs, install the plugs into the fittings, screw them back into the pump and manifold and connect the heater hoses.
FYI, '68's don't have any kind of water valve in the system. Hot water is always flowing into the heater core. The temperature is adjusted by a door that allows/stops air flow across the core into the car. If the seals are bad in the heater box, the hot air will leak into the car.
BillL

I bought such a valve at O'Reilly's. Just tell them what you want it for.

I purchased a control valve installed it --no problem. I used the heater hose from the pump to the firewall. No leaks everything cool. Five miles form my house the temp went whacko. It went from 200--230-260-200. Pulled over and it went back to 180 where it runs all the time. Tried again because it cooled off --same thing --it went up to 260. So I opened the valve went right to 180. Any ideas ??????

Check your thermostat. Since you shut off the flow to the heater core you have no bypass flow when the thermostat is closed. Punch a couple of 1/8" holes in the body of the thermostat so that you have some water flow around the thermostat when it is closed. This will let it sense the water temperature. The holes also permit any air from forming a pocket under the thermostat.

Squido

Check your thermostat. Since you shut off the flow to the heater core you have no bypass flow when the thermostat is closed.
What's wrong with the bypass built into a small-block water pump casting and the front of the block; or the big-block bypass hose from intake to water pump?