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| | | Forums66 Topics128,013 Posts1,055,312 Members48,419 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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I have an air flow heater in my 54 3100. I have a cable that is labled " T " that operates the flap door on the heater( on the side - to recirculate the cab air). I have an under dash switch looks aftermarket. I have 2 hoses going into the heater from inside the engine compartment, off the water pump...But I don't see a on/off valve inline on one of the hoses ? Does the water just circulate thru the heater..then when i need heat/defrost the switch turns on the squirrel cage and thats when I feel the heat ? The heater hoses look new...did the last owner forget to put the valve back on ? or does the 54 not have it? Thanks Guys
| | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | There should be a valve mounted to the firewall. It is called a Ranco valve. You could use an in-line valve. | | | | | Joined: Sep 2007 Posts: 2,644 Shop Shark | | Shop Shark Joined: Sep 2007 Posts: 2,644 | It's possible that the previous owner left off the valve because it leaked or something. There should be a valve mounted to the inside of the firewall that protrudes into the engine compartment where hoses attach to it. Like cletis said, it's called a Ranco Valve.
The baffle in your heater only diverts the airflow to either the floor or defroster outlets. It does not recirculate the air.
To operate your heater you turn on the fan, adjust the flow of water to control the amount of heat coming out of the heater, and select heater or defroster as desired. | | | | | Joined: Aug 2010 Posts: 368 Shop Shark | | Shop Shark Joined: Aug 2010 Posts: 368 | Woody: I saw the lever on the fan housing that diverts the air flow to floor or defrost....whats the purpose of the tall skinny flap door if not to draw cab air back in....it's drawing air on the back side of the squirrel cage. I'm Just guessing . Jimmi | | | | | Joined: Aug 2010 Posts: 368 Shop Shark | | Shop Shark Joined: Aug 2010 Posts: 368 | Brad : Thanks for the pics.. I understand the knob is wrong...but where can I find the correct lever cable ? Also, My engine compartment looks like your pic,only my hoses are alittle lower and to the left. They connect to 2 tubes. On the inside I don't have a straight rod that is connected from dash to back of firewall....is that the on/off valve ? I just have a switch. thanks | | | | | Joined: Sep 2006 Posts: 3,596 'Bolter | | 'Bolter Joined: Sep 2006 Posts: 3,596 | I would imagine most people buy a plain knob to add to a choke or heater cable I don't know of anyone reproducing the original. Your hoses are just hooked directly to your heater because the valve is missing if you are looking to make it correct you need to run it through the Ranco valve as shown. The bad news is the Ranco valves and repro knobs are available but the other pieces are not reproduced so Swap Meet or eBay is your option. This valve assembly is and early attempt at temperature regulation in the cab not just on/off. When I have sold heaters in the past I include all these various little parts because of the difficulty in finding them. | | | | | Joined: Sep 2007 Posts: 2,644 Shop Shark | | Shop Shark Joined: Sep 2007 Posts: 2,644 | Woody: I saw the lever on the fan housing that diverts the air flow to floor or defrost....whats the purpose of the tall skinny flap door if not to draw cab air back in....it's drawing air on the back side of the squirrel cage. I'm Just guessing . Jimmi Yours must be a newer model or something because mine doesn't have that flap. Sorry for the mis-direction. | | | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | When that flap is open the inner flap is closed and cab air recirculates. When that flap is closed the inner flap is open to allow outside air into the cab. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | The earlier models of that style heater were call "fresh air" because outside air was moved through the heater at all times. The 53-55 models of that heater had the door/flap on the front for recirculating interior air and were called "air flow". That flap/door operates as Cletis describes in the previous post. Look at the illustration and you can see that it shows a partially open flap/door (recirculating a little inside air and letting in a little outside air). Several years ago, the "new owners" of GSPP - Golden State Pickup Parts kindly found me a correct length/knob 54/55 control cable for this style heater (a reproduction cable/knob that they might have made for me?). | | | | | Joined: Aug 2010 Posts: 368 Shop Shark | | Shop Shark Joined: Aug 2010 Posts: 368 | Tim: May I ask the Name & where you got the manual your pulling info and pics from, looks really helpful Thank | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Jimmi, I probably bought that 1954 Chevrolet Truck Accessories brochure off eBay about 8 years ago. It is one of several documents listed on my website. | | | | | Joined: Apr 2010 Posts: 35 New Guy | | New Guy Joined: Apr 2010 Posts: 35 | You can get the heater temp control knob and Ranco valves from Classicparts.com You can pretty much get all the heater stuff from them. There are a couple things they don't have, such as the rubber grommet that cover the heater motor as it sticks out of the cab slightly.
anyway, I have a 350 in mine, I am running the Ranco valve. I believe I have a heater hose coming from water pump to the far left of the heater core. Then coming from my intake I have a heater hose going into the back of the Ranco valve, then a hose coming from the front of the Ranco valve into the Right hand side of the heater core. Basically there are two slots on the heater core and two slots on the Ranco valve for your hoses. You have two slots on the engine, water pump and intake.
Same concept for inline 6 engines, I have a 54' all original too. The heater is is just a blower motor that is controlled by electric, the heater core is where the water comes into and the blower just blows that hot air, that is controlled by you and or the Ranco valve opening and closing, also you can control it to cab or defrost. again check out classicparts, they also have 12 volt motors and also power inverters for using 6v motors with 12v systems.
Only thing I don't know is where the copper wire from the Ranco Valve goes to, I thought it might go to the motor but I am not sure if it is long enough. Does anyone know what I am talking about? | | | | | Joined: Dec 2001 Posts: 14,522 Moderator: Welcome Centre, Southern Bolters, Legion Hall | | Moderator: Welcome Centre, Southern Bolters, Legion Hall Joined: Dec 2001 Posts: 14,522 | That copper "tube" sort of half curls and lays next to the firewall right above/beside the tranny hump. Denny Graham has a pic of it in his photo album but I don't have a direct link right now. | | | | | Joined: Aug 2010 Posts: 368 Shop Shark | | Shop Shark Joined: Aug 2010 Posts: 368 | Dear 99: I can't find the ranco valve at Classic parts..they only service your valve for you...also, I can't find the dash mounted rod that controls the ranco valve ( see Brads pic)..... Anyone know who carries that stuff ? also, Tim I just ordered a accessory & owners manual to go along with the one I already have... Thanks Jimmi V.
| | | | | Joined: Jan 2010 Posts: 4,263 Shop Shark | | Shop Shark Joined: Jan 2010 Posts: 4,263 | Jimmi V
Try posting in the parts wanted section of this forum. I had good sucess posting there.
Good Luck | | | | | Joined: Feb 2001 Posts: 4,095 'Bolter | | 'Bolter Joined: Feb 2001 Posts: 4,095 |
Ron, The Computer Greek I love therefore I am.1954 3100 Chevy truckIn the Gallery 2017 Buick Encore See more pix1960 MGA Roadster Sold 7/18/2017
| | | | | Joined: Apr 2010 Posts: 35 New Guy | | New Guy Joined: Apr 2010 Posts: 35 | jimmi,
yeah I guess classic parts only services the valve. I thought you can buy one but you have to give them yours as a core charge. Anyway, maybe these aren't being reproed rather just refurbished. I would call that Jim Carter place, it still seems iffy if you can just buy one. I did see a valve on ebay completely redone for about 70 or 80 bucks.
Well, my valve leaks and my heater core leaks, so I went ahead and ordered up the aftermarket heater box, comes with everything you will need to run it, I mean everything. I am just going to run a shut off valve so in the summer I won't let hot water in and winter it will always be running through.
Lastly, I know what you mean about hat rod that connects to the Ranco valve. I have mine, but I don't have the "dash" attachment, I guess you can't find everything aftermarket. So yeah gotta keep it old school and hunt for it. | | | | | Joined: Jan 2010 Posts: 4,263 Shop Shark | | Shop Shark Joined: Jan 2010 Posts: 4,263 | try http://www.heatervalves.net/He rebuilds Ranco Heater Valves. sells a few rebuilt valves with no core required used rods and brackets also. Good Luck | | |
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