M38A1 Fuel Pump Questions

[cody10414]

Three decades ago I picked up what I was told was a fuel/vac pump for a M38A1. Soon after I went to a MV parts dealer and purchased a rebuild kit for it. Here is a pic of the pump, pieces together just for the pic:

So way back then I clean 'er all up, put the new valves in the topside, then notice the new mid and lower diaphragms are way too large. Procrastinated a bit too long about resolving the problem and it ended up in a box I just found recently. Here is a pic that shows the new and old parts:

A few minutes ago when I was taking the pics, I noticed the rebuild kit gasket is a 3-holer. The only markings I can pull off the pump is "AC" on the top cover and 1539810 on the inside of the lowermost housing.

So here comes my ignant questions:
-Do I have the pump assy for a M38A1? Looking illustrations in manuals, I am pretty sure I do. Any clues to what series pump the rebuild kit I have is to?
-Or do I possibly have the rebuild kit for a M38A1 pump and the wrong pump housing? The wrong gasket throws me on this one.
-Or do have neither?

As always, I appreciate any assistance I can get here!

Dayzed and confuzed.

Cody

[wesk]

It's a shame you don't have the kit part number. The kit looks like a BK or BN series pump kity. The M38A1 uses a CU or CY series pump. I didn't see any 1539810 #'s listed but that doesn't mean they aren't correct.

[cody10414]

Wes, thanks for the info.

Alas, it wasn't 1539810, so belay my last! I have too many post-it notes here, its actually 5592300 in the lower housing.

I'm working with a reprint TM 9-1828A here so the pictures I can see aren't so good but it does look the BK series diaphragms, now that you have pointed that out.

Thought I might be able to pull the kit p/n from my old receipts but no luck...

Cody

[wesk]

They are the housing casting numbers. The assembly number is on the side of the angled mounting flange (often called the face). Stamped very finely.

[cody10414]

Wes,

Wow! there is a number there, 4260.

Found another number in the hole below the mounting flange:
5592834

Awful close to the ones in the SNLs:
M38 AC-5592293 (ORD 9 SNL G-740 1955 fig. 03-2)
M38A1 AC-5592835 (ORD 9 SNL G-758 1956 fig. 03-4)
TM 9-2320-208-34P, same AC-5592835

Thanks,
Cody

[SteveJ]

When I was looking for a rebuild kit for my M38 fuel pump I called "Then and Now" and they told me to look for a number stamped on the face of the mounting flange. Based on that number they sent me the rebuild kit for both ends and everything fit perfect.

http://www.maritimedragracing.com/then_ ... motive.htm

[wesk]

It was quite common for AC to use only the last four numbers of their part numbers on the mounting flange of the pump or the mounting face of the pump for our Canadian friends.

In your case the the 4260 is actually the same 5594260 found at the top of page 83 in the M38A1 ORD 9.

[cody10414]

Thanks to you both!

I finally got that ID resolved and what looks like a great source for premium rebuild kit!!!!

-Cody

[53a1]

I think there should be a one way valve on the front next to the hand pump shaft. Did the rebuild kit include this?

[wesk]

No. There was a check valve used there with the fording system plumbing on very early M38A1's and just a vent cap used on later M38A1's.

[Kendall]

As a follow-up to this post- I have an early (1952) M38A1 that should have the connector check valve. Are they available anywhere? Where should I look to get one?
Thanks, Kendall

[wesk]

There is a very helpful Canadian member, Remi, that found these in Canada and has been selling them to us.
http://willysmjeeps.com/v2/modules.php? ... heck+valve