In tank pump question

[digitaldust]

is there any harm in running with the in tank pump now working ?
I have 26Volts on one wire and the fuse is ok , I think the pump may be dead
however the deuce starts great and runs fine , maybe a little less power ?

 

[armytruck63]

Are you sure the in-tank pump is not working? Start your engine and build up air. Then shut off the engine, but leave the battery switch on. Walk over to the tank, open the cap, and listen inside for the sound of the electric motor running.

Of course, the motor can run and the pump not have any output. Test number two is to remove the fuel line from the top of the tank and turn the pump on again. If nothing, or only a dribble comes out, your pump is not working.

Don't forget to shut off the battery switch when you're done testing to prevent hydro-lock.

There is no harm in running the deuce with the in-tank pump not working, but you might have reduced fuel flow. However, if you lose prime in your fuel system, you might not be able to start the truck.

 

[CatMan]

In Tank Pump Question

In the latest issue of the MVPA magazine Supply Line, there is a complete article about the intank pumps, their design life, failure modes, testing and how to contact the manufacturer who will sell a new replacement pump assembly to private owners. The pump is still in production and is used on other current military vehicles. They are not repairable.

And yes, at some point you will not be able to restart the truck. Usually at the farthest point from your home. I speak from experiance.

Cat Man

 

[dmetalmiki]

now running?

or do you mean not running? ..well on my m62 35 54s (wrecker deuce 5ton) I actually have a seperate isolator switch to turn off the in tank pump (onl)y. and once driving on the highway I turn the pump off. this saves wear and and replacing worn out or dodgey pumps all the time. My deuce does not need the i.t. pump even for starting. (if they drop power for any reason I simply flick the switch back on.
Also 5 ton engines seem to be more fussy about the pump running than do deuces.

 

[digitaldust]

I dont hear anything comming from the pump. I wonder if the ground is not conducting .

 

[JCKnife]

I recently replaced my fuel pump. My suspicion is the old one hasn't been running right since I bought the truck; I don't think it harmed anything, but now that I'm running WMO I needed a working fuel pump. Olympic Controls, $225.

 

[General Mcgregor]

You could always crack your bleeder screw on top of the secondaries housing and turn the switch on. If it is running at all you will get some kind of flow from it, even just a dribble.
(unless your pumping cavity has fallen apart which happens)

 

[dmetalmiki]

also ( far from home or just fail)..the trucks will usually allways start with a (very) short tow start..even when cranking with the sarter will not. And actually I have repaired these pumps..I just angle grind the case open ( off the old weld) to repair or replcace veins or replace brushes.
When re assembling however the RE-WELD (ABSALUTLY (MUST)) be carried out by professionally competant MIG WELDER. . ( as fuel cooling the "works would NOT be a great result!!) If at all UNSURE do NOT attempt it.

 

[flyxpl]

Were is the fuse located ?? I just recovered a deuce that has been sitting for about three years . I believe the pump is not working , I have power at the plug but I hear nothing . A shot of ether and it started right up seems to start fine now without ether .

 

[General Mcgregor]

Were is the fuse located ?? I just recovered a deuce that has been sitting for about three years . I believe the pump is not working , I have power at the plug but I hear nothing . A shot of ether and it started right up seems to start fine now without ether .

The fuse is located on top of the pump. (top of tank) Remove the 3 cap nuts then remove the cap.

 

[flyxpl]

My problem was the fuse . Pump works now .

 

[USAFSS-ColdWarrior]

Imagine that ............

 

[digitaldust]

well my fuse is ok. I get 24v on one of the wires that plugs into the pump . maybe its my wiring harness I'm going to try a jumper for ground.
Has anyone tried a after market out side the tank pump?

 

[goldwing2000]

well my fuse is ok. I get 24v on one of the wires that plugs into the pump . maybe its my wiring harness I'm going to try a jumper for ground.
Has anyone tried a after market out side the tank pump?

Don't know if you ever got this resolved but the pump fuse is *after* the plug. That is, between the plug and the pump. You could have 24v to the plug and still not be getting anything to the pump below.
What do mean by you have "24v on one of the wires"? Are you putting your voltmeter leads into the two wires in the plug or between one wire and chassis ground?

 

[digitaldust]

well I had a melt down today. my pump burned up as best it could in a air tight egg.
So I cut it up and learned about it. Its a magnetic drive . there is no shaft from motor to the impeller. that was shocking. the impeller is ok the motor is a melted POS that seemed to be packed under pressure. as I cut into the case I found it started hissing like a old compressor tank.
anyhow I'm building a new bump with old parts.
I will post photos .

btw drill out the plug at the dimples and it comes right out. its a ring and the case is punched to hold the connector onto the pump. very not user serviceable.

Another note on the magnetic motor drive . maybe it acts like a clutch if the fuel is OIL and its shick it does not over heat the motor turning the impeller.

or its just a great way to have a sealed electric motor in a fuel tank ?

 

[goldwing2000]

Ick. Hopefully I have better luck with mine then you had with yours. Going to inspect my no-spin later today.

I think the mag drive isn't so much to protect from viscosity as from solid particles. Jam the impeller with a twig and you don't shear the pump. Just a guess...

Fyi, modern-day in-tank pumps actually push the fuel through the motor itself to help with cooling.