Water shut off valve?
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,242
Likes: 12
From: Kalispell MT
Water shut off valve?
My '70 BB non A/C needs a cooling system overhaul and I'm making my list of parts to replace. Radiator will be a DeWitts and I've found an AC Delco heater core. Expansion tank is in good shape.
In some of the catalogs I see a water shut off valve that diverts the water flow around the heater core and it appears to be vacuum actuated. Where is this located? Does my car even have one? Before my heater core started leaking into the floor and I bypassed it a couple of weeks ago, you could get temperature control using the thumb wheel control between H & C but I haven't been able to locate a shut off valve yet. What am I missing?
In some of the catalogs I see a water shut off valve that diverts the water flow around the heater core and it appears to be vacuum actuated. Where is this located? Does my car even have one? Before my heater core started leaking into the floor and I bypassed it a couple of weeks ago, you could get temperature control using the thumb wheel control between H & C but I haven't been able to locate a shut off valve yet. What am I missing?
Drifting
Joined: May 2004
Posts: 1,442
Likes: 2
From: Flanders NJ
The vacuum operated one only works when the AC is turned on, so you should not have one. You can get shut off valves at Auto Zone, Advance, Napa. I installed one on both hoses to & from the heater core. That way the heater core is isolated from the hot water. They are manual valves, close in spring then open in the fall to get heat.
My '82 used a 5/8" one and the other one was 3/4". There are plenty of threads on this, do a search and you will find all kinds of info.
My '82 used a 5/8" one and the other one was 3/4". There are plenty of threads on this, do a search and you will find all kinds of info.
Le Mans Master
Joined: Aug 2006
Posts: 7,413
Likes: 1,552
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Hi, on my 74 the car heater is controled by the thumb switch that supplies vacuum to the switch which is spliced into the heater hose under the hood on the pass side.
Look in a catalog and you'll see what it looks like for your car. Pete.
Look in a catalog and you'll see what it looks like for your car. Pete.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
Ray,
It's an inexpensive solution requiring no vacuum. My 1967 non-A/C coupe was terribly hot in the cabin during the summer months with the constant flow of coolant through the heater core. That $10.00 plumbing valve really cut down on interior heat. And the only harm done is to a short length of 3/4" heater hose. A completely reversible mod.
It's an inexpensive solution requiring no vacuum. My 1967 non-A/C coupe was terribly hot in the cabin during the summer months with the constant flow of coolant through the heater core. That $10.00 plumbing valve really cut down on interior heat. And the only harm done is to a short length of 3/4" heater hose. A completely reversible mod.
