This valve on the thermostat, does that block coolant from entering the heater core? I tried to turn the valve by hand, but it's tight. How is this valve open and closed? Thanks, JD
It is a valve to cut off the water to the heater. (The outlet comes out the bottom.) Loosen the brass hex packing nut. Packing is probably gunked up. You should be able to turn handle once the brass nut is loosened up. Once you get it freed up, tighten the nut until it quits leaking. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
It prevents full engine temp coolant from flowing through the heater core. It would have to help some in keeping the cab cooler (maybe less hot would be a better term) than if engine temp coolant was present. How much it helps??? Beats me. I've got one on my '38 and have run it both ways. I've not been able to tell a difference. Now I just leave it on all the time.
Last edited by Tiny; 06/20/20197:45 PM.
Save a life, adopt a senior shelter pet. The three main causes of blindness: Cataracts, Politics, Religion. Name your dog Naked so you can walk Naked in the park.
This may put it in perspective. I just took a road trip thru some hot country in my F250 7.3L diesel that has no AC. When it got over about 75F outside, when we stopped for a short time, and restarted, the fan would blow hot air into the cab from the heat built up in the heater box. The fix was to put a valve in the heater hose. That kept that blast of hot air from cooking us on startup. It did help with comfort.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I can see where it might make a noticeable difference if you have a fresh air heater. You could have air crossing the core any time the vehicle moves. My '38 isn't a fresh air heater so to get the heat into the passenger compartment I have to turn the fan on. There may be a bit of convection heating with the fan off but not enough for me to notice it.
Save a life, adopt a senior shelter pet. The three main causes of blindness: Cataracts, Politics, Religion. Name your dog Naked so you can walk Naked in the park.
I know nothing about what heater is in his truck or what was available. My point is as I stated, in MY vehicle it makes little difference whether the valve is open or closed because air only flow across the core with the fan on. IF his vehicle has the same type of heater his experience would likely be the same.
Last edited by Tiny; 06/22/201912:14 AM.
Save a life, adopt a senior shelter pet. The three main causes of blindness: Cataracts, Politics, Religion. Name your dog Naked so you can walk Naked in the park.
OK, Tiny He is talking about his 1951 truck. Sorry - I was trying to help him. What kind of heater do you have in your 1938 truck? Presumably, it does not have an "automatic" Ranco heater control valve (as was available in in the "deluxe" heaters 1951)?
JD, what style heater do you have in your truck? Recirculating - no Ranco valve Air Flow - Ranco valve Fresh Air - Ranco valve Other, non-GM
