Fuel pump diaphram red spring

[gjz30075]

I've taken apart many AC fuel pumps and this is the first one that I've seen that has a
red spring. All others I've seen have been natural (or blackened with age). The diaphram
was also red and says to be replaced with 1524905 only so I'm 'assuming' that the spring
and diaphram work together.

Does anyone know if this spring (and presumably the diaphram) are of a different pressure
rating than the natural spring?

caveat: this was a non working pump that's been in my stash for years.

[oldelanman]

The diaphragm looks identical to the one from my S4 pump with the same wording on it .. I would think they are all the same and it's just the spring that determines the pump pressure. Can't recall what colour spring my pump has and unfortunately it's about the only part I didn't take a photo of when I rebuilt it. Does your pump have a number stamped on the body?

[gjz30075]

Yes.
I wonder if the first several digits are the date code, meaning yours is October (K) of 1970 and
mine would be October of 1969, first digit being the year. I realize this is Ford parlance and these
are AC pumps, though. Is yours a Stromberg carbed car?

[oldelanman]

Yes mine is a Stromberg car but built prior to 1970 so your date code theory looks unlikely, unless of course my car had a replacement pump early in it's life. Maybe the numbers at the end indicate the date which would mean mine (695) is May '69 and yours (776) is June '77
I think it's more likely to be a part number or spec number. These pumps were widely used in different applications so I think they would need to be identified in some way as externally they all look very similar. Strange though that the stamping was done before the screw holes were drilled making it difficult to decipher.

[gjz30075]

Quite possible on the date codes, Roger. My original Stromberg motor is sitting on a pallet
in my garage, minus its fuel pump. I put in a stroker motor over 25 years ago using a different
pump, so this 'red' pump could be from my Stromberg motor. This is the only commonality that
could be, ie, Stromberg carbs maybe require a different pressure (maybe), hence, a different
spring. But as you mentioned, these pump applications are quite varied, so who knows

Thanks for the insights!

[alanr]

I have an old AC Delco Catalogue on disk and the correct model AC fuel pump part numbers shown for the Elan/+2 are:-
461-197 and 7971280.
It also lists the same number pump for the Escort/Capri 1300/1600/GT only.
Interestingly though for all other Ford's,Cortina/Corsair etc it lists a different numbers but what those differences are I have no idea. It could be just fuel inlet/outlet orientation I don't know.
As others have said this type of pump was widely used on lots of different make of cars.but they will all have no doubt all have different springs and therefore deliver different fuel pressures.
The spring will obviously determine the delivered pressure.

Alan.

[Craven]

Thought it was well known, the original Lotus supplied pump, had the top rotated one hole round for better connection alignment and also had the large coil spring inside change to give the correct and different delivery pressure from standard pump. Pump Part No 026 E 0370, Spring Part No 856940.

[alanr]

Hi Ron,
The number you quote is the Ford number for the pump and not the AC number which i quoted earlier.
Question is, Is the number you quote for the spring, a Ford number or an AC number? My first thoughts are that it looks like an AC number.

Alan