BobT-47P15 Posted September 4, 2015 Report Posted September 4, 2015 Sometimes the heater shutoff valve is worn out or missing on the old flatheads. I was going through my photo album and found this picture. You can get one of these valves at O'Reilly Auto (or probably at others as well)......and they are not very expensive. This is, of course, the manual (turn it yourself) valve as opposed to the larger cable operated item. I turn mine off for summer and back open for winter. Just posting this info in case someone can't find such a valve. Is a Murray brand part. This is the "fancier" cable controlled unit. I don't think you can find this one at the auto store. Quote
desoto1939 Posted September 4, 2015 Report Posted September 4, 2015 The cable controlled one would be only used if you have the control knob on your lower dash panel Rich HArtung Quote
deathbound Posted September 4, 2015 Report Posted September 4, 2015 Is this for '47 only? Just have to ask, didn't want this thread to go in the same direction as your non-pressurized radiator cap thread. All kidding aside, I'm guessing it's probably universal across MOST, if not all the Mopar flathead 6 line. Quote
BobT-47P15 Posted September 4, 2015 Author Report Posted September 4, 2015 I would suppose that valve was used on later models with a push/pull knob for turning on the heat. Then, there would be a second knob........the fan/blower control on many models. Not sure if the more basic Mopar heater had a blower. My heater is the "fancier" one with the blower motor on the front..............and a cable to turn on the water even though it is not currently in operation. Quote
desoto1939 Posted September 4, 2015 Report Posted September 4, 2015 The cable controlled one would be only used if you have the control knob on your lower dash panel Rich HArtung MY 39 Desoto uses the manual control shut off value at the back of the head. I also have one up at the bypass connection. This way if I have to remove the heater I just disconnect the hoses at the heater and drin the hose and do not have to drain the radiator. So at least 39 Dodge/Desoto/Chrysler and Ply used the manual shutoff value at the back of the head. Rich HArtung Quote
46Ply Posted October 10, 2015 Report Posted October 10, 2015 I'm trying to install the valve as mentioned above in this thread. But the threading on the valve does not want to screw in easily. I can force it with a wrench, but the plug I removed will thread in easily by hand at least 5 threads. The new valve will not go in more than 2 or 3 threads by hand. Obviously, I'm no mechanic, but is this normal? Should I proceed, or return the valve? Quote
Don Coatney Posted October 10, 2015 Report Posted October 10, 2015 The thread size is 1/2" IPS (iron pipe size) This is a tapered thread that gets tighter as you screw it in. However if what you bought is by chance a metric size it will not work. Can you confirm the piece you bought is IPS? Call the supplier? Quote
46Ply Posted October 10, 2015 Report Posted October 10, 2015 (edited) Thanks Don, Appreciate the reply. I think I'm good, just wanted to be sure I don't mess up the threads in the head. The part I bought is the same one posted below. Edited October 10, 2015 by 46Ply Quote
Seaside Pete Posted October 12, 2015 Report Posted October 12, 2015 I Just checked out the part number you show on O'Reilly's site and using their fitment guide by typing in 1947 plymouth p15 and it says that "it will not fit your vehicle"? Have you actually fitted one of those BOB T. Pete Quote
Plymouthy Adams Posted October 12, 2015 Report Posted October 12, 2015 their chart aside Pete, many people are running this very same universal control valve on their cars...it is the option you have if you wish to control the flow manually Quote
46Ply Posted October 12, 2015 Report Posted October 12, 2015 Pete/Plymouthy, I noticed the same thing, but based on the info in this post I bought it anyway, and it fits perfectly. Some of the vendors don't know what they're selling. You can find the same part listed elsewhere claiming that it does fit. Quote
Seaside Pete Posted October 14, 2015 Report Posted October 14, 2015 Great, because the one at the rear of my block has seized. Pete Quote
ptwothree Posted October 14, 2015 Report Posted October 14, 2015 (edited) The thread size is 1/2" IPS (iron pipe size) This is a tapered thread that gets tighter as you screw it in. However if what you bought is by chance a metric size it will not work. Can you confirm the piece you bought is IPS? Call the supplier? Here is a Four Seasons 74682. Looks like it might work, but I'm no plumber. It has a 5/8" hose barb and a 3/8" npt. Can this be adapted some how? It's a pull to close type so maybe not. Edited October 14, 2015 by ptwothree Quote
Don Coatney Posted October 14, 2015 Report Posted October 14, 2015 Here is a Four Seasons 74682. Looks like it might work, but I'm no plumber. It has a 5/8" hose barb and a 3/8" npt. Can this be adapted some how? It's a pull to close type so maybe not. My aging eye calibration may be off. 3/8" IPS or NPT is probably correct. Quote
BobT-47P15 Posted October 16, 2015 Author Report Posted October 16, 2015 Also, guys........you who have early to mid 50s Plymouths (and maybe others) might want to check O'Reilly's stores for new wheel cylinders (and I can't recall what other related items). I bought some front wheel cylinders for my 47 P15, and they fit, but are not quite correct. When installing some new front brake hoses, the connector was not quite at the original angle......but we got the hoses on anyway. Just putting this out as something else you may be able to get locally instead of shopping eBay, etc. Quote
Dajudge Posted November 8, 2015 Report Posted November 8, 2015 (edited) I'm missing something. Does anyone have a good drawing or picture of how to plumb the heater? I think my confusion is that our truck is running the water from the head to the water pump. This is where the water to the heater is supposed to come from. Where did the water to the pump come from originally? Then from the heater back to the pump is it just a "T"? Thanks Andy PS: Knock wood, the truck has been doing great for my daughter, she leaves out at 5:45 am for band every morning. She puts about 15 to 20 miles a day on her old Dodge and it is getting her to and from school fine. Just starting to get a little chilly in the am. She would like a little heat. Edited November 8, 2015 by Dajudge Quote
DonaldSmith Posted November 8, 2015 Report Posted November 8, 2015 Here's a photo of the engine and cowl of my 47 DeSoto: The line from the shut-off valve at the back of the block goes to the bottom of the heater core(s). The line from the water pump (tubing in my case) goes to the top of the core(s). Don't ask me which way the coolant flows. Quote
Young Ed Posted November 8, 2015 Report Posted November 8, 2015 Do you have a hose running from the back of the head to the water pump? If so someone has bypassed the heater. You need a second piece of hose one from the WP to the heater and then one to the connection at the back of the head. Quote
Don Coatney Posted November 8, 2015 Report Posted November 8, 2015 The heater has 2 connections. One from the back of the head to the heater. The back of the head is the hottest so the flow is from the back of the head, through the heater core and then to the suction side of the water pump with the second hose. Hope this helps. Quote
Dajudge Posted November 8, 2015 Report Posted November 8, 2015 (edited) Thanks Don that's what I thought. I guess what I am missing is how does the shut off valve work? I thought you could shut the water off to the heater in the summer time. I don't see how this works when the heater is simply put in between the head and the radiator. Edited November 8, 2015 by Dajudge Quote
Don Coatney Posted November 8, 2015 Report Posted November 8, 2015 The shut off valve simply stops flow through the heater core. No flow is required between the back of the head and the suction side of the water pump. You could plug both the water outlet in the back of the head and the water inlet to the pump with no effect on engine cooling. The heater was an option when these vehicles were new and those sold without a heater had both holes plugged. Quote
Dajudge Posted November 9, 2015 Report Posted November 9, 2015 Ding, Ding, Ding!!!! I got it now Don! My confusion was that our truck has a hose going from the head to the pump. You just made me realize that that shouldn't be there unless you have a heater. Now it makes total sense. Thank you very much!! Quote
46Ply Posted November 9, 2015 Report Posted November 9, 2015 This might be another dumb question, but does it make any difference which direction the water goes through the heater core? Quote
TodFitch Posted November 9, 2015 Report Posted November 9, 2015 This might be another dumb question, but does it make any difference which direction the water goes through the heater core? Probably not much but I prefer to use the top as an inlet and the bottom as an outlet on the heater. Quote
DonaldSmith Posted November 9, 2015 Report Posted November 9, 2015 Per my post 17, the coolant goes from the back of the block to the bottom of the heater core(s). I'm sure Mother Mopar had a reason. Quote
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