Radiator Identification for Non-Pressurized Systems

[JBNeal]

When it comes to truck radiators, most folks just want them to fit inside the engine compartment and to keep the engine cooled off sufficiently without needing much attention.  When I first started working on my '48, I took my radiator to a local radiator repairman for a checkup, he ran a garden hose through it and called it good, said it looked like some of his work from a long time ago, elaborated by saying the flat-finned core was probably from an old Pontiac...there was evidence in the upper tank that the original neck was dead centered, not on the driver side.  In '95, I found two mostly intact parts trucks in a local wrecking yard, '48 and '53 half tons, with the distinctive honeycomb core radiators, which my '48 did not have.  I snagged the radiator in their '48, but when I went back a few months later to get some more parts with my lawn mowing $$$, I was informed both trucks had gone to the crusher just a few days prior...!

 

While doing some research on cooling system interchange part numbers, I came across some information in the April '54 edition of the '48-'53 parts manual, and it got me to look into my stash of parts as well as the radiators in the trucks in the yard.  And to my surprise, even though these radiators looked the same at a glance, it turns out I've got a menagerie of radiators that are related but have different p#s, filler necks, overflow tubes, and core thicknesses.  My parts manual muddies up the waters even further with some conflicting information regarding replacement radiator caps.

 

But the one thing that I can say for certain is that even with these variations, it appears that the cooling systems for the B-series and Route Vans used non-pressurized systems from the factory.  I looked into the flat-fender Power Wagons and there's indications that some systems were not pressurized thru '56 but others were depending on other criteria...I didn't want to go down that rabbit hole as I have before with other research that crossed Pilot-House parts with Power Wagons, WCs and M-37s.  This is based on the parts manuals I have and information gleaned from a few Power Wagon websites.

 

The radiator caps for these non-pressurized radiators can be identified by their size, either 2-11/16" OD (776379) or 2-1/4" OD (795519):

• Cap 776379 is listed for all B-1 & B-2 except R/T/V/Y
• Cap 795519 is listed for all B-3 & B-4 except R/T/V/Y

Several vendors offer non-pressurized caps depending on year specified but not by size.  Local alternatives may be available that have a slightly different look, possibly with more moderate pricing:

Radiator Cap:  Mopar 776379  -  Stant 10232  -  NAPA 7031475

                          Mopar 795519  -  Stant 10203  -  NAPA 7031400

 

Studying my parts manual, the breakdown for replacement radiators is by model:

Radiator Core:  Mopar 1272945  ==  B-1-B, B-2-B, B-3-B, B-3-C, B-4-B, B-4-C

                            Mopar 1272947  ==  B-1-C, B-1-D, B-2-C, B-2-D, B-3-D, B-4-D

The replacement radiator cap specified in a note is 795519 for both radiators...apparently Dodge was specifying the newer style production radiators with the smaller fill neck to replace the older style with the larger fill neck that had gone out of production.  

 

Looking through my stack of spare radiators and radiators in my trucks, I was scratching my head at what I was finding:

• '48 B-1-B:  1195170 was pulled from a '48 parts truck, has the large fill neck, a discharge right overflow tube, and 2-1/4" core
• '48 B-1-D:  1195178 has the large fill neck, a discharge right overflow tube, and 2-1/4" core
• '49 B-1-D:  1195178 has the large fill neck, a discharge left overflow tube, and 2-1/4" core
• '51 B-3-D:  1272446 has the small fill neck, a discharge right overflow tube, and 2-1/4" core
• '52 B-3-B:  1272446 has the small fill neck, a discharge right overflow tube, and 2-1/4" core
• '53 B-4-B:  1272446 has the small fill neck, a discharge right overflow tube, and 2-1/4" core
• spare (1):  1195178 has the large fill neck, a discharge right overflow tube, and 2-3/4" core
• spare (2):  1272446 has the small fill neck, a discharge left overflow tube, and 2-1/4" core
• spare (3):  1272947 has the small fill neck, a discharge right overflow tube, and 2-1/2" core
• spare (4):  same as spare (3)

 

As reported earlier, the 1195170 was superseded by 1272945.  But I cannot locate the other part numbers in my parts books, and at a glance, these radiators all look the same with respect to tanks, core thickness, and inlets + outlets.  The differences in overflow tube discharge direction has me a little stumped, as the left discharge radiators do not appear to have been repaired, so maybe these are deviations from Dodge specifications.  From a practical standpoint, the left discharge seems to be a defect as any sharp right turn or traversing a slope at an angle will cause coolant to drain out, whereas the right discharge would allow more coolant to stay in the tank.  The 2-3/4" core might be a repair job, but it is a honeycomb core, so maybe that too is a deviation.

 

At any rate, these part numbers might be helpful in determining if your radiator might be relatively original, a replacement, or "custom"

Edited December 18, 2019 by JBNeal
revised info

[Dodgeb4ya]

Thanks for all this good information!

The parts books sure skip over some of the radiator part numbers..

[ggdad1951]

Agreed these have never been pressurized rads.  When building FEF the guy who checked out the rad for a leak (crack in lower tank wall) pointed out these are non pressurized.  And as can be seen below...the weep line is below the cap seal area.  Great catalog of info ^^^.

 

[bkahler]

Brian,

 

Great article.

 

The NAPA 7031400 comes back as a 14-18 psi cap. 

 

The Stant 10203 looks good although pressure is listed as N/A which I assume means no pressure    

 

Interestingly my radiator part number appears to be 972210F which doesn't seem to fall anywhere in your list.

 

 

[Charlie Stephenson]

Thank You.  Charlie Stephenson

[JBNeal]

Doing a quick google search shows a guy selling a 972210 on eBay for a 46-48 DeSoto...and it sorta looks like one of my spares...

 

The rad.cap data is kinda misleading much the same way in there are some variations between manufacturers' and vendors' websites, much like the shock absorber info I dug thru...pressurized rad.caps will have some kind of thermostatic spring between the cap and sealing plunger, whereas non-pressurized rad.caps will only have a positive seal and locking tangs.  If I read it right, the NAPA caps are made by Motorad, and their data matched the Stant data...I looked at some generic info for tractor rad.caps just to compare and it all seemed to mirror the Stant and Motorad data, with similar pricing.  So for all I know, the Stant, Motorad, Balkamp, NAPA, Murray, etc. rad.caps are all made in the same building managed by some guy who looks suspiciously like Tommy Callahan ?

 

I was stewing on the different p#s and my nocturnal problem solver woke me up this morning to take a 2nd look at the brackets and tanks...so I examined these radiators and sure enough, there are slight differences in the mounting bracket stampings and hole patterns, as well as different # of tank vertical ribs, different upper tank inlet tube lengths, and different lower tank outlets + drain plug orientation...so these radiators may all function the same way but some are more well-built and less expensive than others ?

[bkahler]

10 minutes ago, JBNeal said:

Doing a quick google search shows a guy selling a 972210 on eBay for a 46-48 DeSoto...and it sorta looks like one of my spares...

 

This radiator looks exactly like mine although mine doesn't have the gash in the tank!

 

Now I'm wondering, could mine be a replacement radiator from a DeSoto?  

 

Just found that it could also have come from a 46 - 48 Chrysler Windsor.  Just when you think you have things figured out then out of left field comes this!  One of these days if you can lay your hands on that spare radiator let me know and I'll shoot  you some dimensions to compare to.

 

10 minutes ago, JBNeal said:

The rad.cap data is kinda misleading much the same way in there are some variations between manufacturers' and vendors' websites, much like the shock absorber info I dug thru...pressurized rad.caps will have some kind of thermostatic spring between the cap and sealing plunger, whereas non-pressurized rad.caps will only have a positive seal and locking tangs.  If I read it right, the NAPA caps are made by Motorad, and their data matched the Stant data...I looked at some generic info for tractor rad.caps just to compare and it all seemed to mirror the Stant and Motorad data, with similar pricing.  So for all I know, the Stant, Motorad, Balkamp, NAPA, Murray, etc. rad.caps are all made in the same building managed by some guy who looks suspiciously like Tommy Callahan ?

 

I was stewing on the different p#s and my nocturnal problem solver woke me up this morning to take a 2nd look at the brackets and tanks...so I examined these radiators and sure enough, there are slight differences in the mounting bracket stampings and hole patterns, as well as different # of tank vertical ribs, different upper tank inlet tube lengths, and different lower tank outlets + drain plug orientation...so these radiators may all function the same way but some are more well-built and less expensive than others ?

 

The Stant 10203 cap looks correct.  I didn't see a picture of the Napa cap.

 

 

[Tim in NB]

Always amazes me when part numbers are listed that some apply to Canadian trucks and some are completely different. Canadian parts manuals are broken into two manuals: 1948-1950 truck parts list (WM-4252) DE and DF Series (these are the Dodge's in Canada) and FM and FN (these are the Fargo's in Canada). 1951-1953 truck parts list (WM-4294) DG-DH series and FO-FP series. Technically, we didn't have any trucks called the "B" series in Canada. 

With reference to Mr Neals post above on radiator caps and radiator cores from the Canadian parts books:

 

Radiator cap 776379 fits all models listed in the 1948-1950 parts list.

Radiator cap 1243326 fits all models listed in the 1951-1953 parts list.

 

There are three radiator cores listed for 1948-1950 trucks and four listed for 1951-1953

 

Radiator core 1195518 fits DE-1, FM-1, DF-1, FN-1 (1948-1950 1/2 tons only)

Radiator core 1195305 fits DE/FM-2, 3, 4, 5, DF/FN-2, 3, 4, 5 (1948-1950 1 tons -some 3 tons)

Radiator core 1195307 fits DE-6, FM-6, DF-6, FN-6 (1948-1950 some 3 tons only)

Radiator core 1273691 fits DG-1, FO-1, DH-1, FP-1 (1951-1953 1/2 tons only)

Radiator core 1273692 fits DG/FO-2, 3, 4, DH-2, FP-2 (DG/FO 1 tons -2tons & DH/FP 1 tons only)

Radiator core 1272883 fits DG/FO-5, 6, DH/FP-4, 5 (DG/FO 3 tons & DH/FP 2-some 3 tons)

Radiator core 1390847 fits DH/FP-6, 7 (some 3 tons & 3-1/2 tons)

 

No 3/4 ton trucks are listed in the parts books in Canada in this era, although my owners manual (WM-4226) lists an FN-2 as a 3/4-1 ton.

 

A few part number changes are referenced in a 1954 Chryco Parts Buyers Guide (WM4316) as below:

 

1948-1950 1/2 tons only use radiator core 1272126 and cap 1243326

1948-1950 1 tons only use radiator core 1272128 and cap 1243326

 

There are also a few part number changes (mostly obsolete) referenced in a July 1, 1965 Chryco, Cancelled, Obsolete and Superseded Parts list (WM4698) as below:

 

Radiator core 1195518 use 1243326 (cap) & 1272126 (core)

Radiator core 1195305 obs sp (obsolete)

Radiator core 1273691 obs sp

Radiator core 1390847 obs sp

Radiator core 1272126 obs sp

 

I have a 1950 Fargo FN-2 (1 ton), my buddy has a 1950 Fargo FN-1 (1/2 ton ) and we have a 1950 Dodge DF-1 parts truck and there seems to be some differences between them all in certain areas. Probably depends on when built and of course what previous owners have retrofitted. My truck actually has the 1195305 radiator still in it!

 

Tim

 

 

 

[JBNeal]

while doing research, I found a replacement option that might be a viable alternative to the shot-in-the-dark of buying used radiators...while studying my spares, I noticed one of them might have core damage that is irreparable, and I'm positive I bought that one on eBay over 10 years ago...d'ohhhhhh...

 

anyways, it looks like US Radiator has a decent replacement that should fit nicely...they have several models to choose from, although I believe these should also work for 1-ton models as well.  They aren't giving them away, but these are new not refurbished radiators with warranties, so that could be a viable solution to a replacement need