Fuel Tank Questions

[rmesgt]

Hello everyone! I finally got my deuce to run, but it wasn't long before it shut off. I figured it had a "Fuel Related Issue" and I was correct. I extracted about 25 gallons of yellow goo, sludge, water, and weird stuff from the tank using a syphon hose. I then decided to remove the fuel tank, bring it home, and clean it out. Thankfully, whomever designed this truck was a genius as removing the tank is probably the EASIEST thing to do.

While cleaning out my tank, I decided to remove the bracket that holds the tiny in-tank pump (booster pump?). The bracket was held in place by a variety of screws (sheet metal, wood, sheet rock, etc.). Once the fasteners were removed, I extracted the bracket and the tiny pump. It took about 10 seconds to see why they put an external fuel pump on top of the tank. I also noticed that someone cut off the plug that was supposed to power the in-tank pump. The external pump on top the tank is from O'Reilly Auto and is a 12V unit. It is powered from one battery with a toggle switch on the dash to activate it.

I have been reading about a possible In-Tank replacement pump. IE: The Parker Pump for the Bradley. My search of the Auction Site (sometimes known as Sleezebay) didn't yield any results. If anyone can direct me to this pump I would appreciate it. The next issue I need help with is the 10 screws that hold the fuel pump bracket to the top of the tank. They look like #10-32 x .75 machine screws. Unfortunately, previous ownership has used so many different types of fasteners that the holes are wallowed and the threads are jacked. I will probably have to drill/tap these holes to the next size up (1/4-20?) I will also need a new gasket. I suppose some of the parts places such as Hillbilly Wizard, Big Mikes, etc will have this gasket. If anyone knows a part number for this gasket from a local vendor such as O'Reilly or Auto Zone, that would be helpful as well. Finally, for this thread, how can I obtain the milspec plug that fits into the connection on the fuel pump bracket?

As always, and with a great deal of sincerity, thank you all for your willingness to help and for the knowledge you share...

 

[cattlerepairman]

Here is the gasket: https://www.bigmikesmotorpool.com/p...mounting-gasket-for-multifuel-trucks-10917063

Or you simply cut your own...it is a simple round shape.

Yes, the in-tank pump is the "right" way; it also has become a bit pricey, in the $350-400 range. Here is one possible source: https://www.easternsurplus.net/Part...k-Fuel-Pump-Multifuel-Submersible-M35A2-M54A2

That is why some members use an external pump. 24V is available and it is reported that these work very well. They do not need a separate switch; they can be operated through the regular in-tank fuel pump circuit.

Here is some info on the external pump option: https://www.steelsoldiers.com/threads/24v-inline-fuel-pump.61149/


Not sure which end of the fuel pump electrical connector you need; here is the one on the "lid": https://www.eriksmilitarysurplus.com/inelfuputope1.html
The end that plugs into it is a regular Packard rubber shell connector, single pin.

 

[rmesgt]

Here is the gasket: https://www.bigmikesmotorpool.com/p...mounting-gasket-for-multifuel-trucks-10917063

Or you simply cut your own...it is a simple round shape.

Yes, the in-tank pump is the "right" way; it also has become a bit pricey, in the $350-400 range. Here is one possible source: https://www.easternsurplus.net/Part...k-Fuel-Pump-Multifuel-Submersible-M35A2-M54A2

That is why some members use an external pump. 24V is available and it is reported that these work very well. They do not need a separate switch; they can be operated through the regular in-tank fuel pump circuit.

Here is some info on the external pump option: https://www.steelsoldiers.com/threads/24v-inline-fuel-pump.61149/


Not sure which end of the fuel pump electrical connector you need; here is the one on the "lid": https://www.eriksmilitarysurplus.com/inelfuputope1.html
The end that plugs into it is a regular Packard rubber shell connector, single pin.

Holy Cow..! You have all the answers! Thank you so much for the links and knowledge. I have followed your links and I am leaning towards the COM 5203 In Tank replacement pump. It is expensive, but it seems like a better fit. I have an external pump (12v) that looks like the Airtex E8131, but again, it is tied to a toggle switch. If I forget to turn off that switch, I will burn out my pump. I was able to use the 12v pump to start my truck, but with all the junk in the fuel tank and now the lines and filters, it may not start again without a complete clean-out. I downloaded the parts spreadsheet and saw that the filter elements are available through NAPA. I will order a set to replace the two on the truck. Are these filters the same for both canisters? I have been reading about 6 and 10 micron elements, but I don't know enough to make an informed purchase. Your thoughts???

 

[M35fan]

Holy Cow..! You have all the answers! Thank you so much for the links and knowledge. I have followed your links and I am leaning towards the COM 5203 In Tank replacement pump. It is expensive, but it seems like a better fit. I have an external pump (12v) that looks like the Airtex E8131, but again, it is tied to a toggle switch. If I forget to turn off that switch, I will burn out my pump. I was able to use the 12v pump to start my truck, but with all the junk in the fuel tank and now the lines and filters, it may not start again without a complete clean-out. I downloaded the parts spreadsheet and saw that the filter elements are available through NAPA. I will order a set to replace the two on the truck. Are these filters the same for both canisters? I have been reading about 6 and 10 micron elements, but I don't know enough to make an informed purchase. Your thoughts???

The two canister filters on the engine are the same. You should also have a primary filter located on the passenger side, underneath the alternator/generator. It is often forgotten.

 

[HDN]

I believe another option for you is to not replace the electric fuel pump. The truck's IP should be able to suck fuel out of the tank just fine - I remember reading some posts about M35A2 owners who had dead in-tank pumps and didn't know it. None of the A3s were built with in-tank pumps.

But if you open up the fuel system at all, like replacing fuel filters, you'll be cranking a bit on and off to get your prime back.

 

[rmesgt]

The two canister filters on the engine are the same. You should also have a primary filter located on the passenger side, underneath the alternator/generator. It is often forgotten.

Thank you for letting me know where that darn Primary filter is located. Based on the diagram I used, I was looking under the truck near the bumper. I feel like an idiot. As I was looking for it, I thought "Nobody would put a fuel filter here" and they didn't, which is why I couldn't find it. Do you know a part number for this filter element? I have one for the Secondary and Final, but I didn't see one for the primary. Perhaps someone long ago did the right thing and made all of the fuel filters the same.... Nah.... That would be expecting too much....

 

[KN6KXR]

-Yes the easiest will be to drill and tap the buggered ones.
-Cut the gasket yourself.
-Use a 24V marine rated pump mounted to the frame rail like a good Walbro they run about $225. Wire it to the original spot. You'll never have to deal with it again. Did mine this way and also ran parker push lock abrasion resistant fuel hose ($$) and eliminated a bunch of hard line. MUCH better.
-It will run fine with the pump dead until you go to change the filters. It'll never prime again without the lift pump. I know this for a fact.
-I have a bunch of fuel filters but after I go through them I'm going to all modern cartridge spin on style. These old filters and their can gaskets are the pits. It's not 1956 anymore we've gotten better at this....

 

[M35fan]

Thank you for letting me know where that darn Primary filter is located. Based on the diagram I used, I was looking under the truck near the bumper. I feel like an idiot. As I was looking for it, I thought "Nobody would put a fuel filter here" and they didn't, which is why I couldn't find it. Do you know a part number for this filter element? I have one for the Secondary and Final, but I didn't see one for the primary. Perhaps someone long ago did the right thing and made all of the fuel filters the same.... Nah.... That would be expecting too much....

The primary filter I use is a Wix 33511. Napa part number for the same filter is 3511. I've read some posts that say this filter is not an exact fit, but I have had no problems with mine so far. There is a direct replacement available from Memphis Equipment, that can be cleaned and re-used. The difference in size is because the primary filter is also a water separator. Getting at the canister to change it is tricky. I had already replaced my burnt out generator with a Delco alternator, which gave me a bit more room to work. A good soldier B is very helpful.

 

[cattlerepairman]

My five cents is that replacing the military alternator with a civilian one (more output at half the size; much more space around it) and replacing the stock primary filter with a spin-on cartridge setup are worthwhile modifications.

Civilian alternators 21SI, 22SI and 27SI are usually used. Single wire. No more lifting a 50lbs alternator out of the engine compartment!!

 

[rmesgt]

Here is the gasket: https://www.bigmikesmotorpool.com/p...mounting-gasket-for-multifuel-trucks-10917063

Or you simply cut your own...it is a simple round shape.

Yes, the in-tank pump is the "right" way; it also has become a bit pricey, in the $350-400 range. Here is one possible source: https://www.easternsurplus.net/Part...k-Fuel-Pump-Multifuel-Submersible-M35A2-M54A2

That is why some members use an external pump. 24V is available and it is reported that these work very well. They do not need a separate switch; they can be operated through the regular in-tank fuel pump circuit.

Here is some info on the external pump option: https://www.steelsoldiers.com/threads/24v-inline-fuel-pump.61149/


Not sure which end of the fuel pump electrical connector you need; here is the one on the "lid": https://www.eriksmilitarysurplus.com/inelfuputope1.html
The end that plugs into it is a regular Packard rubber shell connector, single pin.

I looked again at the Eastern Surplus pump. It is listed at $399.00, but I also noticed a $125.00 Core Fee. Since I don't have a core, the new price is $525.00 + shipping. I think I will have to go with an external lift pump such as the FRB-23-2 for less than half of the Eastern Surplus pump. Your thoughts??

 

[KN6KXR]

Walbro is a great pump. Don't forget to check ebay for these. I scored two 6067 series (not marine rated) for under $50 each awhile ago. Right now there's a 6093 (7 psi, 43 gph) for $125 obo and a 6096 (4 psi, 33 gph) for $60. These are older pumps with the old numbers but both are marine rated and will work just fine. If I needed one the 6096 would do fine I think the OEM one doesn't run over 4 psi and 33 gph is plenty of flow. Also they lift something crazy like 48" so if you mount it right over the tank on the frame like I did mine it'll likely flow more than rated.

Takes a bit of searching to cross the old numbers to the new but you stand to save $150 so what the heck. Don't forget to budget nice fittings and line from your local hose shop I think I dropped a Franklin there. Worked for me.

 

[rmesgt]

Walbro is a great pump. Don't forget to check ebay for these. I scored two 6067 series (not marine rated) for under $50 each awhile ago. Right now there's a 6093 (7 psi, 43 gph) for $125 obo and a 6096 (4 psi, 33 gph) for $60. These are older pumps with the old numbers but both are marine rated and will work just fine. If I needed one the 6096 would do fine I think the OEM one doesn't run over 4 psi and 33 gph is plenty of flow. Also they lift something crazy like 48" so if you mount it right over the tank on the frame like I did mine it'll likely flow more than rated.

Takes a bit of searching to cross the old numbers to the new but you stand to save $150 so what the heck. Don't forget to budget nice fittings and line from your local hose shop I think I dropped a Franklin there. Worked for me.

Thank you for searching on my behalf! I will check ebay shortly to see if I can find these. I have been wondering about fuel line. It seems my deuce is using copper pipe in some places and clear plastic tubing in other places. I think previous owners have added/modified a significant portion of the fuel system. It seems there is WIDE variety of options in regards to fuel lines. Rubber, Plastic, Copper, and 3/8" DOT Airline (teflon lined). What do you recommend?? I have a feeling I will need to replace every line, fitting, and filter.

 

[rmesgt]

Walbro is a great pump. Don't forget to check ebay for these. I scored two 6067 series (not marine rated) for under $50 each awhile ago. Right now there's a 6093 (7 psi, 43 gph) for $125 obo and a 6096 (4 psi, 33 gph) for $60. These are older pumps with the old numbers but both are marine rated and will work just fine. If I needed one the 6096 would do fine I think the OEM one doesn't run over 4 psi and 33 gph is plenty of flow. Also they lift something crazy like 48" so if you mount it right over the tank on the frame like I did mine it'll likely flow more than rated.

Takes a bit of searching to cross the old numbers to the new but you stand to save $150 so what the heck. Don't forget to budget nice fittings and line from your local hose shop I think I dropped a Franklin there. Worked for me.

Pump ordered! Won't get it for a while, but that's OK. It looks like I will have to build a bracket to mount it to my truck. Yes, another project! Thank you for your help. I will get my truck running right as rain before too long...

 

[KN6KXR]

There's a small local shop near me that has all the hydraulic fittings and can make lines and whatnot. They are called "The Hose Shop". There will be one near you. Go make friends. You own an Army truck.....

I went in with my pump and pictures with a tape measure in the pic. Also some of the fittings. They set me up with Parker Push-Lok stuff. Since I have a dump bed access was easy and I put the pump right on the frame rail by drilling and bolting using the flanges made for it on the pump. If I didn't have a dump bed I may have mounted it further on the rail maybe by the engine bay area behind the primary filter separator. Remember these have a small pickup screen in them that needs to be accessed once in awhile. I left my old pump in place and it pulls through. Sounds like this might be a problem for your application but frankly just any kind of dip tube maybe an inch from the bottom of the tank will do. I'm sure you can adapt the flange and make a tube to pull from the bottom. If you can make a stainless dip tube that would be awesome.

For the line I ran brass push-lok fittings with JIC adapters to get the hose orientation correct. At the 90 degree turn (from tank to tuck in to frame rail) I used a push-lok elbow. The original hard line I'm sure is durable but it's a pain to work with and hard to get tucked away in the rail. Remember that up to the high pressure pump you are only running maybe 7psi so flare fittings and hard pipe are not needed. After the pump they are but push-lok will be fine before.

For fuel line they set me up with Parker 1/2" 821-8 WP line. This line is rated 300psi but that's not the reason to buy it as push-lok isn't rated for anything near that. The reason to buy this line is that it's rated for all fuel types, is reinforced and has a great abrasion jacket on the outside. I ran this up to my current original primary fuel filter. Later on when I swap that for a cartridge style modern one I'll continue the run. The line was the most expensive it was $10.30 per foot. Yep gets real pricey....

I'm not going to have any worries with this setup. Vibration won't cause any cracks in the line. If I do tear it I can cut and install a push-lok union. It will flex with the truck and is a premium product. The Walbro pumps are really top notch. I'm not going to worry about the old gas, clean used oil, premix or other crap I blend in to my multi fuel (I run about 20% "other" fuel and the rest #2 ULSD).

At the end of the day it was a bit of money but what I spent on lines and fittings I saved on the pump. I took my time and double heat shrunk the positive splice to the new pump, made sure it was grounded well (even used a cute little star washer!), thought it out and executed with maintenance in mind. There's plenty to worry about with these trucks but the list is one item less now. And so it goes one thing at a time!

Hope that helps.