Correct factory fitted radiator cap?

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Peewee
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Correct factory fitted radiator cap?

Post by Peewee » Fri Jun 24, 2011 12:52 pm

A friend of me (Doc Uwe) asked me something to tell me about this radiator cap.

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Is this the cap that is mentioned in the TM´s as Stant Mfg. No 6455A?

Jon´s page http://jeepdraw.com/PART_COLOURS.htm only refers to the AC radiator caps, until now.


The original wrapping had a label that read.

Ford - GPW - 8100-A

Radiator Pressure Type

PA-636



After I had look through my books and pictures I found a lot of them like this well known, that shows the cap.

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Or this from Jon´s page http://www.jeepdraw.com :

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A really clear picture is in John Farley´s War-Time Jeep 2 book, that shows a Ford GPW at site 235
and Willys MB at site 225 und 226.
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Re: Correct factory fitted radiator cap?

Post by Joe Gopan » Fri Jun 24, 2011 3:41 pm

TThe cap in the photo appears to be other than a Jeep radiator cap, take a close look. It definitely is not an OEM AC Willys or GPW factory cap. The depth of the valve looks off. It should be about 5/8" from the brass seal.
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Re: Correct factory fitted radiator cap?

Post by Peewee » Tue Jun 28, 2011 1:42 pm

Here is a pic of the original wrapping

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Ford - GPW - 8100-A

Radiator Pressure Type

PA-636


I have compared the cap with my original AC Willys caps, it has the same dimensions and fit perfect the radiator.
For sure it is not an OEM AC Willys or GPW cap, but the question is still, was this cap OEM too.

As I said, my Willys Parts Lists refers to the AC and the following cap: Stant Mfg. No 6455A
For example the TM-10-1612 Parts List Jan. 15. 1943 site 33
Willys part no. A-1215 Ford part no. GPW-8100 Radiator filler cap assembly (AC Spark Plug Co. No. 846709) (Stant Mfg. No. 6455A)
Sorry I have no Ford TM´s available.

I found clear pictures with the AC style cap, but also with this cap style.
On these pictures the engine bays looks like new, so I assume these caps where not only motorpool correct.
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Re: Correct factory fitted radiator cap?

Post by Joe Gopan » Tue Jun 28, 2011 2:18 pm

Maybe it was the angle the photo was taken at, but it sure looks like the portion of the valve where it rests onthe gasket inside the neck is too deep. I have AC "F" Cap and an NOS WWII Issue 4# AC cap, but no Stant brand to compare side to side.
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Re: Correct factory fitted radiator cap?

Post by oskold » Tue Oct 30, 2012 5:46 am

John Farley's "The Standardised War-Time Jeep" has pictures of both types of radiator caps.
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Re: Correct factory fitted radiator cap?

Post by Tom Wolboldt » Tue Oct 30, 2012 6:53 am

Hello Peewee,

You wrote:
For sure it is not an OEM AC Willys or GPW cap, but the question is still, was this cap OEM too.
Yes, the Slant 4 lb. non " F " marked radiator cap was one of the caps released for use on the GPW. I would have to dig in my notes to find the actual release date.

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Re: Correct factory fitted radiator cap?

Post by lt.luke » Tue Oct 30, 2012 9:16 am

As that label doesn't appear to have a repack date, I can't see why anyone would argue with it. I sure wouldn't!

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Re: Correct factory fitted radiator cap?

Post by Wessels » Tue Mar 04, 2014 10:56 pm

Hi Tom...

Were you ever able to confirm the release date of the "non F marked" Stant radiator caps for use on GPW's?

Thanks in advance!
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Re: Correct factory fitted radiator cap?

Post by Chuck Lutz » Wed Mar 05, 2014 7:41 am

In case Tom does not run across the date the STANT caps were authorized......

The photo of the Rockhampton crated GPWs being assembled shows hood numbers in the range of 20393941 and I believe Tom identified them as Richmond jeeps...I'm guessing around April or so of 1943.
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Re: Correct factory fitted radiator cap?

Post by artificer » Wed Mar 05, 2014 11:46 am

If that is the correct cap there is a fibre seal between it & fitted in the radiator neck.
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Re: Correct factory fitted radiator cap?

Post by Bill M » Wed Mar 05, 2014 12:54 pm

Great photos peewee, thank you.
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Re: Correct factory fitted radiator cap?

Post by 42cargo » Sun May 04, 2014 10:45 am

I also recently acquired one of these. The packaging was missing part of the label, but everything else looks the same. I'll be using it to replace the one that came on my December '44 GPW. (The addition of the safety chain on the old unit was a nice touch in terms of preventing you from losing the cap, but it clearly stands out like a sore thumb.)


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Re: Correct factory fitted radiator cap?

Post by Chuck Lutz » Sun May 04, 2014 10:58 am

AFAIK, the round STANT #6455A is crossreferenced to the GPW-8100A3
The STANT with the ears on it is possibly the GPW-8100A2
The AC seen below is the GPW-8100A:
GPW Radiator Cap F Marked.jpg
GPW Radiator Cap F Marked.jpg (94.07 KiB) Viewed 5012 times
Check your TMs for the correct cap for the contract your GPW was built under for more information.
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Re: Correct factory fitted radiator cap?

Post by Joe Gopan » Sun May 04, 2014 1:50 pm

The above cap appears to be AC without the script F" stamped near the 4# pressure marking.
Last edited by Joe Gopan on Mon May 05, 2014 2:33 pm, edited 1 time in total.
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Re: Correct factory fitted radiator cap?

Post by Chuck Lutz » Sun May 04, 2014 4:23 pm

I do not know of any GPW-8100A caps that are STANT...only AC made that model AFAIK
Likewise, I have not seen an AC that is in a box marked GPW-8100A2 or GPW-8100A3....those are the ones that STANT made.

Can you post the WO part numbers and the mfger/mfger part number for the radiator caps used on the MBs?
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