Fuel Supply Hose ID

[Gunny65]

My truck, M934A2, would not start this morning for the first time since I have owned it. I checked the fuel lines as suggested in other forum posts and found that the fuel line where the small filter is located is sucking air. You could hear it when I pushed on the filter and line. I looked in the TM and could not find the part number. I do not have a local company who can make me one, I have called around. Closest is 2 hours away. Here is a picture of the hose and filter. It is the hose that connects the metallic fuel line from the tank to the engine pump (where you prime the fuel system). I need the part number for both ends as the connectors sizes are different. It seems like the TM goes from the fuel pump system and injector lines to the tank lines and skips this area. At least I am sure I missed it but spent a good amount of time going back and forth. The long line is 12" and the short is 5". The only number I could get off the line itself is, 20511312 and that does not show up in the 24P TM. I think the other line has, 20511313. Both tags are super hard to read due to corrosion. Either way though, those part numbers do not show up in the TM. I found them online but it was incorporated with a bunch of other information I could not decipher. Ugh, frustrations... Anybody have a good part number or replacement part number?

 

[juanprado]

I am not totally versed on A2 but that looks like a bubba modified hack. Looks like somebody cut the hose and added an inline gasoline filter. I hope I am wrong but I have never seen or heard of that set up.

 

[Suprman]

Put a piece of copper pipe in place of the filter and use 2 hose clamps on either side. That should get you running temporarily. The plumbing supply houses usually have a variety of adapters they may have something that will screw on each end with barbs on the other ends and you can just get some fuel line and put one together yourself. Been there done that. A few times.

 

[Gunny65]

I did a basic ID check on the hose ends. While the OD of the fittings are different, the internal diameter is the same. So, disregard the part where I said the two ends were different sizes. They are, but not where it counts, the same thread ID. It looks to be the same thread pitch as well. I didn't actually measure thread pitch, just eyeballed it.

I will use the copper tube idea if it comes to needing it moved. Right now the truck is okay where it sits.

I did some additional reading and looking at the hose. The hose itself looks to be a high pressure type hose. I don't think you need a high pressure hose in that spot. Or anywhere on the intake side from the tank to the pump. After the pump, sure but not before. Am I correct on that? If I can get the correct fittings, with barbs as Suprman pointed out, the line should work fine.

I didn't see in the TM where it had a filter there but again I couldn't find the hose location in the TM anyway. You could be correct Juan. The filter simply had to hose clamps on each end. It definitely wasn't high pressure.

I am going to see if I can find some hydraulic hose ends or something similar and make my own. I would rather have the correct part though so if anyone can add any informational help, it would be greatly appreciated. Thanks.

 

[Suprman]

Napa sells fuel rated hose? It's not a high pressure line. Take the old end to the supply house most are good at finding you what you need. I have done the hose barb thing for these hoses without issue. I got the idea originally from a truck I had won that the military had done the same thing.

 

[Castle Bravo]

I have seen several A2s with that filter on them. On a truck I drove from Ohio to Arizona, it decided to plug up and I was stuck on the side of the road without any replacement. Luckily, there was a metal spike of some kind inside the truck and I used that to poke a hole in the filter so that fuel could pass through it directly and I was able to resume travel.

I would do what Suprman said, use barbs, hose clamps, and fuel hose.

 

[Trk2bg]

Your hose ends appear to be field replaceable type. You should be able to thread them off and onto a new hose.

 

[Gunny65]

Trk2bg, I just found this out today. You are correct.

I went to three different local places so they could see the fittings. Nobody knew what they were or could reproduce them. I didn't know anything about them either. However, a guy at CarQuest knew about them and showed me how to take them apart. They had the correct hose available as well. Total price for one new fitting and a hose was $19. One of the fittings he couldn't get apart so I just bought a new one. CarQuest, who would have figured. Really, I have never found them much help in any other part of the U.S. I took some pictures and will post them of the process just in case anyone else has this problem. Mine is mostly due to where I live. When I called around yesterday, everybody said no. So, I figured I would go show them physically. Good thing I did.

 

[Gunny65]

Pictures of Field Replaceable fittings on the 939 Series trucks

Now, I am not sure if other series trucks have these or not. I suspect they do but all I have in front of me is my M934. The following pics will hopefully help others in the future.

This picture shows how the end fits on the hose and what the internals look like. These come in two pieces (the ones I have dealt with). The first piece has threads on the interior and screws onto the hose "In Reverse". So lefty is NOT loosey. Push as you turn LEFT and it will screw down onto the hose. I found that you do not want to screw it on until it butts up against the top. Then you can't get the threads of the second piece started.



Here it just shows the order in which it goes on the hose.


At this point I had to put a light coat of oil on the end of the second piece in order to get it to go into the hose as I screwed it into the first piece. It was pushing the hose out of the first fixture. Once I put some oil on it, and then made sure the hose was not butted up against the end of the first piece, it went smoothly.


Once it got hand tight, I put the first piece in the vice (just snug enough so it didn't turn, don't smash it). Then I used a crescent wrench to finish screwing the second piece in. Hold the hose tightly when you are putting the second piece on so it does not rotate. Watch to make sure it is not pushing the hose out as you screw the second piece in. On the new fitting, it had a nut that you can see in the picture that rotated independently of the other two pieces. That was nice. The second/old fitting does not have this and it does make it a bit easier to fit things together.



Here is the original connector. No extra nut to hold onto. Not a big deal though when you are putting it together but taking it apart, it helps a bunch.


Hopefully that helps others should they need to make one of these. It really is easy. I just didn't know they came apart when I started this yesterday. I learned a lot today. These are DOT approved air lines as well. I purchase an air line online about a week ago because I didn't know I could make these myself (with the proper hose). I paid $50 for the hose. It probably would have cost me about $20 if I had known this process last week. They tried to make these trucks relatively easy to repair in the field. I am sure there are many other items on these trucks that can be easily fixed, if you know the process. We will see. Cheers!

 

[infidel got me]

I am not totally versed on A2 but that looks like a bubba modified hack. Looks like somebody cut the hose and added an inline gasoline filter. I hope I am wrong but I have never seen or heard of that set up.

Idk if it was a motorpool thing or a factory design, but both of my A2's had this same setup

 

[Gunny65]

I am torn between not putting the filter back and cutting the new hose and putting it back. I just hate putting it back in because that is where the air leak happened and I lost prime. I guess it is just like most other filters and it is what it is. I would like to put better clamps on the filter ends though. They had the screw/steel strap type hose clamps on it. Are there better clamp styles out there? Ones that clamp tighter and more securely?

 

[juanprado]

I would not cut the hose and use that filter. I have seen some a2 retrofitted with the large canister under the fender for filtering if you don't have it already or add your favorite universal spin on set. Goldneagle I believe has a used large canister available and there was a member here selling a dual spin on add on for the fender to replace the large canister or add one on. Spin ons are nice and easy to change with no mess. I like the large canister filter because of the large surface area and for me it works.

They make constant tension hose clamps that are supposed to keep the sealing with fluctuations in temp. They are used in cooling system applications alot so there is no drips or weeps.

Napa sells them and Carquest should be able to get them also.

http://www.napaonline.com/napa/en/p/BK_7051500_0006394100

http://www.steelsoldiers.com/showth...lter-kit-for-the-M939-series&highlight=filter

 

[Gunny65]

Thanks Juan. I will check into the spin-on type. I really do not want to cut the hose.