M151A2 Fuel Pump

[glcaines]

It appears that my new M151A2 that I purchased at the auction in Alabama recently has a faulty fuel pump. It is currently not pumping any gas at all. I still have to check the fuel lines, but the lines were all replaced by the auction and from the outside they appear new, although that obviously doesn't mean the interior isn't clogged. I'm trying to decide what course to take if the pump turns out to be faulty.
1. Rebuild existing fuel pump with kit from Then and Now Automotive - Relatively easy job and I would know it was rebuilt correctly
2. Purchase a rebuilt pump - Unknown quality
3. Purchase a new production pump - Unknown quality
4. Purchase a new Dodge pump - I believe this is a bad idea based on what I've read.

I'm leaning towards purchasing a rebuild kit and rebuilding it myself. If I go this route, I'll likely purchase two kits and rebuild the pump in my other A2 since it appears to be decades old as well, although it is currently working well.

[rickf]

Either rebuild it using their kit or have them do it for you. NOS pumps have been sitting on shelves for 30-40 years, rubber diaphragms dry out. Unless you know the rebuilder was reputable then that is out. And I have never been convinced the Dodge pumps were correct. Looking at the shoe angle it is different.

[Horst]

rebuild it, it is not more than replacing the diaphragm and the two flapper valves. Matter of minutes.

Before you do that, make sure that there is no leak downstream from the pump to the tank. Even a svery mall leak will prevent the pump from sucking fuel.

[rickf]

That leak can sometimes be in the upper section of metal line in the tank. If there was moisture in the tank (they ALL have moisture) then that tube will be rusty.

[glcaines]

Thanks Guys. I'm going to check it out tomorrow afternoon. I'll start with the lines. I do know that the pickup tube in the tank is good. When I removed it from the original tank, it was pristine-looking inside and out, obviously replaced when the museum restored the A2. The output from the fuel pump is almost completely closed off due to the bend in the rubber fuel line. This isn't causing my problem, but does need to be addressed. I'm installing a 45 deg street elbow there like I did on my other A2. Installing that 45 deg elbow is such an improvement I would recommend everyone with an A2 do the same.

[fowlercal]

GL,

If you go the rebuild route, can you get some pictures of the operation? I have had the pumps apart but could not figure out how to get the diaphragm to release from the fulcrum rod. I didn’t want to damage it any further.

Thanks, Cal

[glcaines]

Well, I checked out the fuel lines - no problem there. I removed the fuel pump and contacted Tom at Then & Now Automotive about a rebuild kit. He wasn't certain what kit I needed and wanted me to dismantle it to look for casting codes inside. The pump is an original Airtex pump, P/N 11640994, which is stamped on the outside. That apparently wasn't enough information, so I ended up sending it to Then & Now for a rebuild. More money than I wanted to spend, but I'm covered up with projects anyway.
Projects:
M35A3: M66 gun ring mounted, but has frozen up and needs to be dismounted and rebuilt, two tires leaking
M274A5 Mule: Magneto being rebuilt, plus steering box worn out and needs rebuilding or replacement, some tie rod ends need replacing
FLU419: Wiring harness being replaced and compressor head being replaced
M1030M1 USMC Diesel Motorcycle: Rear tire cracking and needs replacement
M151A2: Recently received and not yet started or driven to determine what needs to be done

[rickf]

I think that was a good choice, like all government contract stuff those pumps were made by several different companies. Some of them are not rebuildable since the kits are simply not available. He told me it is getting hard to find some of the kits since there is not enough demand for the aftermarket to make them. The very same pump was also made by AC and I am not sure but possibly Carter also.

[csmith]

Not sure what is up with Tom, I wanted rebuild kits, he said he was not sure he had the correct one so I sent him a pump to work from. He rebuilt it, misplaced it, later found it and sent it back to me. On several attempts I have asked about the rebuilt kits as I told him many would want them and I had 5 pumps I wanted to rebuild. No response. The pump he rebuilt works great.

[rickf]

Speaking as a professional rebuilder myself I can shed some light on that. I don't know if this is Tom's thinking but if he sells the kits and someone does the rebuild themselves and misses something it will not run right. First thing these people do is blame the kit and the guy that sold it. Been there, done that. Then, if he is a good businessman that wants to keep a good reputation he sends another kit. This one is out of his pocket, all profit has evaporated. He told me that these kits are getting scarce so I am sure he wants to do the rebuilds himself so he knows it is right and he does not lose a hard to come by kit.
I am not speaking for Tom, Just from my own past experience with carburetors. Same type of dealings.

[csmith]

Yea, your probably right.... sending him my pump so he could part out for kit and getting it back for parts took 9 months. Got one good spare, that should be all I need....

[rickf]

You are saying he took it apart and only sent back some of it? This is information I kind of need to know since I am sending people there for work. If that is what he is doing I will stop.

[csmith]

No they ask me to send a pump to them so they could see if they had kits or to see what they needed to make a kit. Then they rebuilt it and sent it back. No problems, just took a long time and I never get an answer about the kits.

[rickf]

Gotcha.

[glcaines]

I just got my M151A2 pump back from Then and Now. It was very fast service, only a few days. They also returned all of the old parts. The pump looks brand new. The cost was $134.55 including shipping. I won't know how good a job they did until I install it and see if it works and then to see how long it lasts. At the present time I'm very happy with their service. The old parts looked dirty, but the diaphragm wasn't ruptured. Not sure why it didn't pump. Hopefully it does now.
EDIT: The rebuilt fuel pump works great!