What is the difference in fuel pumps, ‘37 Pontiac Straight 8.

[Gingerbread]

Need to rebuild my fuel pump, coming across ‘double ‘  pumps. I  don’t understand. Any help would be appreciated !

[Bloo]

1523109       AH series pump               1937 sixes and eights  

1523110        AJ series double pump   1937 sixes and eights

 

EDIT: Those are GM/Pontiac numbers. Found another source that says the AC numbers are 430 for single and 493 for double.

 

My book is a 37 book, so if the numbers got changed or updated, I don't have that info. This surprises me. I thought all 37s had double pumps. I guess not.

 

A double pump has 2 diaphragms, the first is a fuel pump, and the second is a booster for the vacuum powered windshield wipers. This is desirable, and would have been an extra cost option on any car that offered it both ways.

 

Here is the single section pump on my 36 six. It is not the same series that would be on a 37 eight, but you can get the idea what a single pump looks like. There could be a glass sediment bowl, right side up or upside down that this doesn't have, but there is one line in, one line out, and one diaphragm.

 

 

 Here are some double pumps. These are for Buicks, but illustrate the idea. You can see two diaphragms, an upper and a lower (where there are a bunch of screws holding things together).

 

In addition to lines for fuel in and fuel out adjacent to one diaphragm, there will be vacuum lines both in and out adjacent to the other diaphragm.

 

 

 

 

 

Edited October 4, 2021 by Bloo (see edit history)

[Kornkurt]

I have kits for both pumps.  Single $54.50, double $74.50.  Give me a call with your credit card # and I'll send you a kit with instructions.  They are recently manufactured and compatible with today's gas.  Thanks!  Kurt Kelsey 641-648-9086

[kookie1]

I just did a rebuild on your basic 493, AJ series, double pump for my 37 Pontiac 6 touring sedan about a year ago.   I took pictures before and after to show my family.  If you'd like to see the disassembly/rebuild let me know and I'll email you the lot.   I didn't buy my kit from Kurt but that's a very reasonable charge for a double kit.    You won't do any better anywhere.

 

Edited October 4, 2021 by kookie1
spellink, Ha! (see edit history)

[Gingerbread]

Thank you all , I did call Kurt. Received it in a couple days. Ready to install on the car tomorrow . That’s one step closer to “beep beep “.