1952 M38A1 Fuel Pump rebuilding and questions

jeeperjoe · Post by **jeeperjoe** » Sat Apr 02, 2016 12:13 pm

Does anyone know where I can find instructions for rebuilding the fuel pump or a diagram of the pump? (other than the TM9-1828 manual) I'm wondering if there are more complete instructions anywhere. I'd even be happy to find some decent rebuilding instructions for other similar model AC fuel pumps.

The parts list for my jeep shows a fuel pump with a priming lever but I haven't been able to find a pump with the lever so I'll probably have to use one W/O the lever. Does anyone know when Willys dropped the pump with the lever? Also Army Jeep Parts says that the early pumps used a hook arrangement to connect the diaphrams on both sides but that the later pumps "used turn lock on the vaccum" side. Does anyone know when they changed styles or if there's a way to tell which style I have without taking the pump apart?

Finally, where is the best place to buy a rebuild kit that will stand up to the modern crap that they now sell as gasoline?

Thanks.

PS I'm trying to find or build the CORRECT fuel pump instead of one that merely FITS.

OKCM38CDN · Post by **OKCM38CDN** » Sat Apr 02, 2016 1:17 pm

Try Then and Now, they used to sell kits and will give technical advice over the phone... Kits are based on casting numbers on the lip of the center section...

Hope this helps...

wilfreeman · Post by **wilfreeman** » Sat Apr 02, 2016 2:17 pm

You can download the manual here:
http://willysmjeeps.com/downloads/+TM%2 ... 201952.pdf

Post by **wesk** » Sat Apr 02, 2016 6:01 pm

Assuming you have the TM 9-1828A 1952 edition then you also need the two changes, C-1 & C-2. Both affect the CY & CU series pumps. This is a well written manual and has 5 very good pages detailing the rebuild process. The M38A1 ORD 9 has an excellent illustration and parts list in the ORD 9 SNL G-758.

If you hope to rebuild a correct M38A1 pump with the priming handle you will have to do it yourself. I have heard of no one with spare parts to support the handle pump items. If you send a handle type pump to Then & Now for Overhaul they will rebuild it as a handless pump.

Bob Westerman has an excellent guide published on the CJ3A/CJV35 page:
http://www.cj3a.info/tech/fuelpump.html

Here's a copy of TM 9-1828A with Chg 2
http://www.gvrdeu.org/M38%20Service%20M ... ps1952.pdf

Another general info page:
http://www.allpar.com/fix/fuel/fuel-pumps.html

jeeperjoe · Post by **jeeperjoe** » Sat Apr 02, 2016 6:23 pm

Good info. Thanks Wes!

PS Wes, where did you move the pictures of the parts of the windshield wiper vacuum system to? I had a link but it doesn't work now.

Hawkshadow · Post by **Hawkshadow** » Sat Apr 02, 2016 7:18 pm

Hey Joe,

Check out Page 3 of my build thread. The post from 7 may 2013 shows every thing that comes in the kit from Then and Now. I was very pleased with it. Rebuilt the pump myself and it was an enjoyable and not overly difficult project.

Post by **wesk** » Sat Apr 02, 2016 7:30 pm

Try my sub-album titled M38A1 Parts!

http://www.willysmjeeps.com/v2/modules. ... _album.php

jeeperjoe · Post by **jeeperjoe** » Sat Apr 02, 2016 8:35 pm

Wes,

Hmm. it's not shown in that image. I'm trying to find the part that connects the metal vacuum line coming from the engine to the bottom piece of rubber vacuum hose. The metal line in my M38A1 ends in the top of the glove box with an inverted flare fitting. I'm trying to what they used to connect that to the rubber hose. So far I haven't found anything in any of the photos or the manuals. I'm sure I could make something that would work but I'd just like to get the correct part(s).

Post by **wesk** » Sat Apr 02, 2016 10:53 pm

OK I have gathered the scattered wiper system photos together in a single sub-album titled "Wiper System"
http://www.willysmjeeps.com/v2/modules. ... _album.php

The hose starts here on the end of that tube with paint missing at the end and goes non stop through one firewall clamp, one firewall grommet and the dash grommet to the regulating (kicker) valve.

Jason86 · Post by **Jason86** » Sun Apr 03, 2016 1:52 am

I had to get my pump from ebay and it did not have a handle. If you get a pump and need a priming handle or the clip that retains the handle I got mine from John Bizal at Midwest Military I believe he makes them. As said by others the rebuild kit I just ordered one Friday for my pump from Then and Now Automotive they do not have the kit listed on their website but if you email them and tell them your pump model # they can help you out. They will also ask you what style rod you have. The kit does not come with the springs so let them know if you need them.

jeeperjoe · Post by **jeeperjoe** » Sun Apr 03, 2016 7:22 am

Jason,

Thanks for the tip about the priming handle and clip! I've heard that those parts are the same as those used on other AC fuel pumps so that's one reason that I've been trying to find more detailed information about the fuel pumps such as part numbers. I have been wondering if it's possible to get parts from a different AC fuel pump and add them to mine. But so far, I haven't even been able to come up with any pump that has the priming handle.

jeeperjoe · Post by **jeeperjoe** » Sun Apr 03, 2016 7:41 am

Thanks for the pictures Wes. I have exactly what you show in picture 174 but mine is different than picture 188. That picture shows a rubber hose going from the engine compartment and through the firewall but I have a 3/16" tubing that leads from the Wiper Tee (I THINK!) up through the firewall and into the glove box. It stops about 4" from the dash. I THINK that that is what that tube is for! I don't know what else it might be for. But so far I don't have the Wiper Tee and parts surrounding it so I can't be sure that it will fit. The tube is currently bent over out of the way and I'm not going to try and straighten it out until I get the Wiper Tee and other parts installed since I don't want to bent it any more than necessary.

BTW the Wiper Tee is the part that has the 0.040" restriction in it doesn't it? If I understand correctly, the restriction is just in the connection that goes to the distributor. Correct?

FWIW I'm also going to have to buy or make the tubing line that goes to the distributor. I have parts of it but some jackass cut a section out of the middle and then crushed the ends of the cut off tubing!

I have the fuel pump and some of the other parts on the way so hopefully in a few days I can start putting things together and see what's going on. BTW Does anyone have a Fording Vale and a Fuel shutoff valve that they want to part with?

I THINK that's the only two major parts that I'm still missing.

Post by **wesk** » Sun Apr 03, 2016 7:55 am

If your goal is a correctly plumbed vacuum system then my illustrations are what you want to follow.

BTW the Wiper Tee is the part that has the 0.040" restriction in it doesn't it? If I understand correctly, the restriction is just in the connection that goes to the distributor. Correct?

The .040 restriction is actually in the adapter connector that the distributor line attaches to. The adapter threads into the Tee distributor port. The connector is shown on page 87 of the M38A1 ORD 9 SNL G-758. ORD PN 7348568.

jeeperjoe · Post by **jeeperjoe** » Sun Apr 03, 2016 8:35 am

wesk wrote:If your goal is a correctly plumbed vacuum system then my illustrations are what you want to follow.

BTW the Wiper Tee is the part that has the 0.040" restriction in it doesn't it? If I understand correctly, the restriction is just in the connection that goes to the distributor. Correct?
The .040 restriction is actually in the adapter connector that the distributor line attaches to. The adapter threads into the Tee distributor port. The connector is shown on page 87 of the M38A1 ORD 9 SNL G-758. ORD PN 7348568.

OH, I didn't realize that there was an adapter in there. I hadn't gotten that far into the system yet and hadn't looked at it closely. Thanks for pointing that out!

So you're saying that mine should NOT have metal tube going through the dash?? An all rubber hose arrangement would certainly be easier! But I wonder where that tube in mine came from? FWIW I found two other pieces of bent metal tubing just laying inside the engine compartment and I've yet to figure what they're for either! Mine seems to have all of the tubing that's supposed to be there even though some are cut up and/or disconnected, so I don't any idea what the extra pieces are for.

jeeperjoe · Post by **jeeperjoe** » Sun Apr 03, 2016 8:39 am

Hawkshadow wrote:Hey Joe,

Check out Page 3 of my build thread. The post from 7 may 2013 shows every thing that comes in the kit from Then and Now. I was very pleased with it. Rebuilt the pump myself and it was an enjoyable and not overly difficult project.

Jordan,

I've been reading your rebuild thread. You really went all out didn't you! You mentioned doing a more compete write up about the fuel pump rebuild in the Parts Review section. Did you ever do that? I haven't found it yet. It also looks like your rebuild kit didn't come with springs either.