Radiator Cap Won't fit into the grill shell

[Robbie Horn]

1931 Coupe. I purchased a shiny new chrome radiator cap for my A but it won't fit into the grill shell. It has a lip on the bottom of the cap that is too large for the hole in my grill shell.I found one online at The Early Ford Store in California that would work because it does not have a lip but they are out of them & don't know when they will get some more. I'm currently using a radiator cap that was on the car when I got it. Has anyone else ran into this problem?

[ursus]

My 31 coupe came with some kind of generic non-Model A cap that barely fits and when I tried to install the correct cap I had the same problem. Your photo captures what I found on my car and I'm wondering what is wrong with this.

[J Franklin]

The shell is sitting too high on the radiator or the neck is too Low.

[lrf]

I have an original radiator cap that measures 2 9/16 across, my repo measures 2 5/8. They both fit. Is your overflow tube in the way?

[brokenspoke]

Stock radiator?

[emf]

Sponsored Links (Register now to hide all advertisements)

I have the exact same problem and I blamed it on the repro Brassworks radiator. When I called them to discuss the problem, they answered, "Do you have any idea how many changes were made to that radiator?" When parts are single-sourced, this the the result. I chucked my repro cap in the lathe and removed about 1/4" from the lip.


Frank

[bobbader]

I could be wrong, but in more than one of the pictures, it looks like the radiator neck has less clearance to the opening in the shell on the driver side than on the passenger side. You might try loosening or removing the screws and nuts that hold the shell on to the radiator to see if there is any “wiggle room” to shift the shell around a little bit so the cap might fit. If you can “wiggle” the shell and make the cap fit, you then have to figure out how to modify the shell mounting brackets on the radiator to make it all work together. Obviously, if the brackets are “off by a mile” then the only alternative is to find someone who has a genuine original cap and see if it fits with everything back in place. I note the post showing differences between the diameter of the poster’s original cap and your new repro cap, but there were several different manufacturers of original caps, so this is not necessarily conclusive evidence that the repro is wrong.

[Synchro909]

Originally Posted by emf

I have the exact same problem and I blamed it on the repro Brassworks radiator. When I called them to discuss the problem, they answered, "Do you have any idea how many changes were made to that radiator?" When parts are single-sourced, this the the result. I chucked my repro cap in the lathe and removed about 1/4" from the lip.


Frank

When I bought a Brassworks radiator years ago, I thought I was getting a new, repro radiator. I didn't! What I got was a poorly done re core of an original radiator. That was in about 2014 and it has been to a radiator shop twice since to repair the poor workmanship.
At first, they tried to tell me that what I had was not one of theirs but when I supplied photos including of the Brassworks tag soldered to the under side of the top tank, I heard nothing more. Hmmmm.

[Robbie Horn]

Here's a pic of what I need. 'll probably do what EMF did & cut the lip off.

[Synchro909]

Originally Posted by Robbie Horn

Here's a pic of what I need. 'll probably do what EMF did & cut the lip off.

I doubt that would be the most radical thing that has been done to any of our cars over the years just to keep them going. If it works, I say go for it.

[katy]

Originally Posted by Robbie Horn

I'll probably do what EMF did & cut the lip off.

Sounds like a good plan, much easier than extending the radiator neck.

[bobbader]

The picture you show is a gas cap. Other than the top and the knurl on the edge looking exactly the same as the radiator cap, they are 2 different animals. Nevertheless, good luck whatever you decide.

[Deny1950]

Robbie Horn just ran into this also. What i did is take a die grinder and take the insid lip off of shell, i had shell off for polishing, but that worked fine and no one will ever know. Except you guys lol I was leary of cutting bottom of cap as mentioned leaving a sharp edge, my 2 cents

[J Franklin]

wouldn't it be easier to find a cap of the right size?

[Robbie Horn]

Originally Posted by bobbader

The picture you show is a gas cap. Other than the top and the knurl on the edge looking exactly the same as the radiator cap, they are 2 different animals. Nevertheless, good luck whatever you decide.

https://www.earlyfordstore.com/produ...1-radiator-cap

[Big hammer]

Originally Posted by J Franklin

The shell is sitting too high on the radiator or the neck is too Low.

Or the radiator is setting to low? Maybe add rubber shims under the radiator feet

[The Master Cylinder]

Originally Posted by Big hammer

Or the radiator is setting to low? Maybe add rubber shims under the radiator feet

Isn't the shell bolted to the radiator? If you raise the radiator by installing rubber shims it will also raise the shell.

[bobbader]

Robbie, appreciate the picture and, while the catalog heading suggests it's a radiator cap ......... I think not. If you look up the gas cap from the same supplier, you'll probably see the same picture. My guess is they were lazy and used the same picture for both catalog entries. As I noted, they look the same on top and through the side knurl, but, in reality, the radiator neck and interior clamping mechanism on the cap have smaller inside and outside diameters than the gas cap, so the bottom dimension of the two caps are different as well.

[ryanheacox]

I just got a new plain cap recently and have the same issue. My radiator is an older one from Independent Radiator, the same company that makes the non-brassworks radiators sold by (I believe) Brattons, Snyders and others.

[Swingle]

From the original picture, looks like the shell of the radiator is sitting too high above the radiator, the neck is too low.


I had this oeoblem with one replacement radiator, cap would not fit on it with shell on it. Put radiator on a workbench, with the front facing down. Put a carpenter square up to the top of the neck, was installed crooked. They replaced radiator, no problems with that one.