MarcDeSoto Posted June 5, 2022 Report Share Posted June 5, 2022 I have a 48 DeSoto, and I'm wondering what is that seal in two parts on the crown of the radiator for? My newly purchased junkyard DeSoto radiator has the two plates that the seal goes on, but the seal is long gone. Maybe it's for preventing wind from whistling through the top of the radiator, or to stop the hood from slamming down on the radiator top tank? I don't know, does anyone have a guess? Does anyone sell new a new rubber seal for these radiators? Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted June 5, 2022 Report Share Posted June 5, 2022 (edited) Based on my experience with aircraft pressure cowls it appears the baffle seal is for promoting air flow through the radiator instead of over it. You could get some rubber sheet material from McMaster-Carr if you want to replace the seal. I removed the plate and mounts from my P15 radiator and it cools just fine. Edited June 5, 2022 by Sam Buchanan 2 Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 6, 2022 Report Share Posted June 6, 2022 Pictures how a dried up one looks. 1 Quote Link to comment Share on other sites More sharing options...
joecoozie Posted June 6, 2022 Report Share Posted June 6, 2022 Try Dennis Bickford of Vintage Woodworks in LaLuz New Mexico I believe he sells them. You can make your own but you need old ones for patterns. I did make a few if you cannot find them And yes, as stated, they are for better air circulation. 1 Quote Link to comment Share on other sites More sharing options...
busycoupe Posted June 6, 2022 Report Share Posted June 6, 2022 My car is like Bryan's and I never realized that there was supposed be a seal there. Quote Link to comment Share on other sites More sharing options...
MarcDeSoto Posted June 6, 2022 Author Report Share Posted June 6, 2022 Thanks Brian. Of course the Dodge is different in that the plates and seal are located on the top of radiator/hood support, rather than on the top tank of the radiator like my DeSoto. Quote Link to comment Share on other sites More sharing options...
MarcDeSoto Posted June 6, 2022 Author Report Share Posted June 6, 2022 Another radiator question, should I put on an original radiator cap or try to find a pressurized one? Quote Link to comment Share on other sites More sharing options...
andyd Posted June 6, 2022 Report Share Posted June 6, 2022 If you have an original style radiator then the original style radiator cap is what you should use, you may also find that the actual depth of the radiator cap "hole" will necessitate the style of radiator cap that you use as the original style apart from being rated at a lower pressure will also be longer ..at least thats what i have found......andyd 1 Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 6, 2022 Report Share Posted June 6, 2022 Somewhere I've seen a post about someone ballooning the top of the radiator by using the wrong pressure cap on a non-pressurized radiator. Quote Link to comment Share on other sites More sharing options...
busycoupe Posted June 6, 2022 Report Share Posted June 6, 2022 On my 48 Dodge it is impossible to pressurize the radiator even with a modern pressure cap. The vent is located in the top of the tank away from the filler neck. 3 Quote Link to comment Share on other sites More sharing options...
nonstop Posted June 6, 2022 Report Share Posted June 6, 2022 What dictates the location of the vent? Neither my 1940 Chrysler nor 1951 truck have the domes. Quote Link to comment Share on other sites More sharing options...
MarcDeSoto Posted June 6, 2022 Author Report Share Posted June 6, 2022 Are your radiators original? Good news on my new DeSoto radiator. I did a flow test and it passed easily. I took it to my radiator shop, so I hope it won't cost too much to rebuilt it. Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted June 6, 2022 Report Share Posted June 6, 2022 (edited) 26 minutes ago, MarcDeSoto said: Are your radiators original? Good news on my new DeSoto radiator. I did a flow test and it passed easily. I took it to my radiator shop, so I hope it won't cost too much to rebuilt it. Have it boiled and pressure tested, if it passes, have them apply a fresh coat of paint........and then install it. Edited June 6, 2022 by Sam Buchanan 1 Quote Link to comment Share on other sites More sharing options...
desoto1939 Posted June 7, 2022 Report Share Posted June 7, 2022 On 6/6/2022 at 12:24 AM, MarcDeSoto said: Another radiator question, should I put on an original radiator cap or try to find a pressurized one? Mark Your 46-48 radtior uses an R-3 NON-Pressurized cap that is the same that I use on my 39 desoto. I checked my Atlas catalog to verify the correct cap Number. NO PRESSURIZED CAP IS TO BE USED. Rich Hartung 2 Quote Link to comment Share on other sites More sharing options...
Dan Hiebert Posted June 8, 2022 Report Share Posted June 8, 2022 I haven't checked in a long time, but there used to be templates for those hood seals in the technical section of this site. 2 Quote Link to comment Share on other sites More sharing options...
Bryan Posted June 8, 2022 Report Share Posted June 8, 2022 Wonder if you should not have it pressure tested either? More like leak tested. What if these guys pump it up and it starts ballooning? Quote Link to comment Share on other sites More sharing options...
kencombs Posted June 8, 2022 Report Share Posted June 8, 2022 10 minutes ago, Bryan said: Wonder if you should not have it pressure tested either? More like leak tested. What if these guys pump it up and it starts ballooning? If it were mine, it would get tested. I hate having to remove parts after installation for any reason. Especially ones that could leak on my fresh work. Not that I don't trust the shop, but I'd do it at home. I have a cooling system test kit from Harbor Freight. Not too expensive and works on the car or with a couple of plugs for the inlet and outlet, can test on the bench too. Without the kit, a bicycle inner tube can be used to pressurize to a safe level. Cut the tube and clamp the open ends over the radiator's outlets and either plug the neck or use the cap, depending on pressure cap or not. Now use the tubes air valve to inflate the radiator. The tube's expansion will provide warning of over inflation. 2 Quote Link to comment Share on other sites More sharing options...
greg g Posted June 8, 2022 Report Share Posted June 8, 2022 There is a template for the rubber part in the down loads section. The pieces are mirror image, so on the trmplate was made by tracing the one original piece that was on my car. For material I used some thin walk off mat that was lying around in the garage. The one shape fits both sides. Mine were stapled on with the staples piercing the sheet metal bits. When I redid mine I cut short lengths of mechanics wire to recreate the look of the staples. If your radiator is stock, don't pressure test it above 3 or 4 psi. If there isn't a leak you don't want a careless tech to make one or more. The location of the overflow tube generally indicates whether the radiator was designed for pressure. If it has the dome o n the tank its a zero pressure system.. if the overflow tube is below the cap gasket in the filler tube it is zero pressure. If the relief tube is above the gasket in the filler neck it is a pressure system, the amount of pressure will be determined by the stiffness of the spring pushing the gasket down onto the seat in the filler neck. So do make sure you identify your radiator before the guy puts his tool on it and blows it up. 2 Quote Link to comment Share on other sites More sharing options...
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