Questions about the deuce fuel system

[DieselBob]

So the in tank lift pump, is it rebiuldable?

There really isn't any thing to rebuild. The only part of the pump assembly that comes apart is the lower foot/impeller unit and there really isn't anything to replace.

 

[Lonesome715]

So if it is gunked up and slimy, I am screwed? Buying a new one is not somehting I was planning on.

 

[DieselBob]

You can clean the impeller on the bottom if it is full of crud by flushing it with carb cleaner or the like. There just isn't really anything to take apart and replace as in rebuilding. The motor housing is a sealed unit.

 

[Lonesome715]

So just becuase the out side ic vovered, that does not mean the inside is bad?

 

[DieselBob]

So just becuase the out side ic vovered, that does not mean the inside is bad?

Correct. The motor is sealed with no replaceable seals or bearings. The outer shell is welded to make a one piece shell encasing the motor and magnetic drive coupling,

 

[Lonesome715]

Now that is good to hear. The next time I have some time off that is first on my priority list. I am trying to rais the money for all new spin on filters, I would hate to have to buy a sending unit as well.

 

[Emmett]

The small line that is pinched/broken off is the fuel return line from the IP/ injectors. It goes to that hole in the tank. It's missing the 90 degree flare. The large line is from the lift pump to the IP..... When you turn on the "ignition" the lift pump should start and followed closely by fuel returning back to the tank as it is not being used by the IP.
If the injector return line is not connected I don't know what will happen but it won't be good.

 

[Lonesome715]

Hey I use to live near you, I grew up in Seffner.

Which line out of the three is a vent line?

 

[Lonesome715]

Can you say, icky? This is what I have to work with. Any thoughts or ideas on how to clean them up before I start spraying stuff on them? Also, is there a coating I can get to apply to the clean and bare metal i will have when I am doen that will resist the fuel. used oil, and what ever else I use for go juice? Oh and the tank has a layer of sludge all around it. But I am thinking the shop will make that go away. I hope the price is fair.

 

[DieselBob]

Just my 2 cents but if you have a machine shop local you might take the pump mount / bracket, without the pump, and have them glass bead it. That would clean away the rust and old paint. The pump it's self I would try carb cleaner and a nylon cleaning brush. I would just replace the sending unit. Man that is nasty.

 

[Lonesome715]

I was thinking about that myself. I have access to a sand blasting cabinet but I was not sure if I should blast the metal or not. i know fuel and the others tuff I will use should keep it from rsuting, but there is no telling how long this truck will sit before I get it running.

The arm on the sening unit will not move. It is siezed up good. I was going to try and repair it. It looks like a simple unit, is there a generic version out there or do I have to get a model specific sending unit for that truck?

 

[DieselBob]

They are specific senders. Erik's has them as do others.

Fuel Level Sending Unit For M35A2, MS500040-5

 

[Lonesome715]

Thanks, I guess it would be better in the long run to just spend the money now and be done with it. I'll see if he has all the gaskets I need as well.

 

[Emmett]

I was wrong. The small line you have circled is the vent line....****. The large line at the front of the tank is the return line.
Surprisingly enough, I got a call Sunday to help someone with a fuel tank problem on a M109A3. Needed the lift pump.
Lot's of rotten diesel but we got him going.
The bottom comes off the lift pump so you can clean it up. Don't lose the small ball. Steam cleaning the tank might reveal small holes in the top of the tank. Can be repaired with fiberglass.
Just take your time and avoid strong chemicals that might eat away at wires and seals.

 

[Emmett]

Sorry, I'm in Land O' Lakes. It is nothing odd to see some of these fuel tanks rusty and full of algae. Lift pumps are expensive so try and save the old one if you can.

 

[Lonesome715]

This fuel system is a lok simpler than I thought it was originally. It looks as though I might be able to save the lift pump. The tank looks like it was full of sewage. Hopefully I am getting to it before any real damage has been done.

 

[Emmett]

Yea, when it's that bad, you might as well take everything apart and clean. Fuel filters after that. if you have algae ( and you probably will) you will need to treat the system as cleaning will not clean it all out.
It will upset you to have the engine stalling at power due to the filters getting full of gunk.
Good luck with your stinky project.

 

[Lonesome715]

How do I treat the system after it is cleaned?

 

[Emmett]

You will have to get something like "bio blast" or any other algicide. I got mine through the International Truck supplier here in Tampa. The stuff is very potent and you need gloves, etc while pouring it in the tank. Sure to cure any fungus growing in the system from the old diesel.
I have run into 3 different Deuces with this problem. Comes with the trucks sitting for extended pierods with the old style diesel in the tank. As I understand it, the Ultra low sulfur diesel does nothave this problem but time will tell.

 

[frodobaggins]

Have you applied voltage to the pump to make sure it works yet ? Might want to do that before you get too far along. Good to know now.