1939-48 8-Cylinder Radiator Cap 932676?

[JHaydon]

The radiator cap gasket on my 1948 8-cylinder has disintegrated and is allowing coolant to leak out. 

 

According to a period application chart from Stant, the 8-cylinder cars take a pressurized cap only available from a dealer.  All of the replacements I have found are the non-pressurized version for the 6 cylinder engine (which fits, but Stant suggested it should only be used to drive to the dealer to get the right one).  No mention of the pressure rating, but I think I scraped up somewhere that it could be 4 psi?  

 

The Chrysler parts books say that all 8-cylinders from 1939 through at least 1948 (my most recent book) used the same # 932676 cap -- C23, C24, C26, C27, C30, C33, C36, C37, C39, and C40.   They also listed a replacement gasket # 932675, so if the cap isn't available this at least suggests that I should be able to replace just the gasket.  That would be preferable because the current cap is not only correct, it looks brand-new.  

 

Does anyone know of a source for the 932676 cap or 932675 gasket?  

 

The cap appears to be very close to the current SAE "A" size, so maybe I could harvest the gasket from a new off-the-shelf Stant cap from NAPA?  Has anyone tried that?  

[24Chry48]

I have not tried that, but I would try a new gasket from a newer cap. Or make one out of gasket material. I'm sure that would work. Very little pressure is wanted, just a seal is needed to keep coolant in.

[c49er]

I have only  found one proper C39  cap years ago.

I have always left my 1946-48 Chrysler "8" radiator caps slightly loose and the coolant level down a couple inches. The top tank is huge and deep.

Coolant never runs or leaks out.

This as a C39 Chrysler owner for over 40 years.

You don't want a failure with that radiator! A very large and unique radiator as to the shape and size.

Huge $$$$ to repair properly.

Zero pressure for me.

Your block/D tube and radiator hopefully has no sludge build up.🙂

 

 

 

 

Edited March 30 by c49er (see edit history)

[JHaydon]

Thanks all!  I also reached out to the restorer who agrees that a new gasket either from a new cap or hand-cut should be fine.  

 

He also suggested using a new (4 psi) cap for driving, and keeping the restored original for shows.  I'll get a couple (they're cheap) and if I ruin the gasket on the first one, the other will become the road cap. 

 

C49er, I totally understand about leaving the coolant level a few inches low.  My father and I each made the mistake of topping it up absolutely full the first time driving it... and then wondering why it left so much coolant on the driveway!  Great to have confirmation that we simply overfilled it.