In tank pump failure, pics

[JCKnife]

My truck has NEVER failed to start after 1-2 cranks until today. I just started running WMO filtered through a 5-micron filter. My tank is currently about 60-65% WMO the rest diesel and a little gas.

Opened the draincocks at the secondary and final filters--NOTHING. Even with the accessory switch on, not a drop. At the primary filter I get drip - drip - drip whether the switch is on or not.

I can hear the pump running and in fact it sounds kinda rough, and I've never noticed that before. Tomorrow it's supposed to be in the 60's so I'll wait until then to pull the pump and see what I can see...

 

[Farmun]

Opened the draincocks at the secondary and final filters--NOTHING. Even with the accessory switch on, not a drop. At the primary filter I get drip - drip - drip whether the switch is on or not. .

Been there, done that. Same exact thing with my truck, drips at primary with switch on or off, and dry at the secondaries. I'm close to 10% WMO in the tank right now. Mine is dead as she can be. The in-tank pump is working some, it spit fuel all over the tank and frame rail when the fuel line was disconnected last weekend.

I pulled the fuel shutoff cover this morning, to see if something is sticking in there, but it appears to be functioning as intended. Not sure though, as I'm still researching this particular part.

Next task I'm thinking about is disconnecting the fuel lines, and blowing through them a section at a time to see if there is an obstruction. (Not the injector lines until I get fuel flow to the secondaries).

Let me know if you find anything out of the ordinary, so I can check it on my truck. Good Luck !!!

 

[JCKnife]

Well, good news to start off: I disconnected the fuel line and flipped on the acc. switch and nada. I can sure hear it running (kinda loud and rough compared to usual) but nothing is coming out, not a drop. Hopefully my issue is the same as the OP of this thread. But with about 60-65% WMO in there it's going to be a messy adventure to find out.

Any trick to disconnecting the power to the fuel pump? The little rubber connector is all crusted up with CARC and it's hard to tell where it comes apart. I'll keep tugging and wiggling and hopefully not tear it.

 

[JCKnife]

Well, got the pump out and no, the bottom screen is not off. It's been either screwed or riveted in place, I didn't take time to determine which yet. So something else is at work with mine. It's sitting in a coffee can dripping out right now, and I'm taping garbage bags over the hole in the tank because we've got serious thunderstorms coming in tonight and tomorrow.

The fuel pump gasket is shot for sure. Is that a NAPA-available part? I'll do some searching.

No rush, but I've just got to clean up the work bench and get the pump cleaned up and see what's going on.

Meh, I went ahead and ordered a gasket on ebay. Hopefully it's not a $2 NAPA part. I think the NAPA cross-x list is part of the old site and not available now. Shoulda saved that somewhere.

 

[gimpyrobb]

Let us know about the gasket. I could use a new one.

 

[Darwin T]

FMJ - at least your are just loose in the tank, mine desintegrated into tiny metal frags in the bottom of my tank.

if you have enought fuel at least you can limp home (or to my mechanics shop, he is a life saver).

 

[DieselBob]

I just used the cork sheet in the gasket material pack I picked up at NAPA to make one. My pump failure was that the magnet on the bottom of the motor section came unglued so that even though the motor ran fine the impeller never turned.

 

[JCKnife]

My pump failure was that the magnet on the bottom of the motor section came unglued so that even though the motor ran fine the impeller never turned.

There's not anything (I can find) in the TM about taking apart the pump motor itself. I've got the bottom end of my pump off (4 screws). Further disassembly from this point is not obvious. There are 2 rivets in the bottom plate (the one with the little round screen).

The black disc on top (I guess it's a magnet per DieselBob?) I can turn with my fingers and it does feel connected to the impeller, but it's encountering some resistance at one point in the rotation. Like the vanes are hitting something.

Any advice on next step?

Correction: The black disc (magnet?) is seated in a section that I can slightly manipulate up and down, but not completely remove (at least not with the force used so far...). When I pushed it down snug I was able to rotate it freely without contacting anything. Pretty sure it is still turning the impeller. The screen on the bottom is slightly mucked over; I'm going to get some carb cleaner and blast it.

Still looking for input.

 

[SCSG-G4]

The motor is a sealed unit. Replace when the brushes go bad or it stops turning. You can buy a brand new one from the manufacturer for about $250. Info is in several threads here on the site.

 

[JCKnife]

What are the brushes and how can I tell if they're bad? I can sure hear it running in the tank but it's not pumping fuel...

I also see plenty of other threads where people have these pumps apart but not how they got that way.

 

[Jakob]

I think I have the exact same problem that you do JC. My pump is running, but I don't think it's putting anything out. Let me know what you end up doing with your pump. I'm waiting on ordering anything until I can get back home and flow test mine to be sure.

 

[Varyag]

You could loosen the drain on the primary filter when the engine is not running to see if anything is coming out. That's what i did to test mine. Mine spat WMO in a good solid stream.

 

[JCKnife]

I've got the pump assembly in pieces on the workbench. Going to try bringing in a couple batteries off the boat, wire them up 24v and test out the pump after a few blasts with carb cleaner to see if I can figure out what is going on.

 

[JCKnife]

Can someone give me a little "electric motor 101" on how the motion transfers from the top-half of the in-tank pump to the bottom half? On page 5 you can see pics of both my and DieselBob's pumps disassembled. In both cases there's a black disc (magnet?) exposed and that's pretty much it. Something in the upper half makes the magnet spin, and the magnet is connected to the impeller? Is that right?

 

[DieselBob]

The black magnet in the picture I posted is normally cemented in the cup that is attached to the motor shaft. All this is enclosed in the casing that makes the top unit of the pump. The lower part that you can remove has a similar magnet that is driven, buy the magnetic field and is attached to the impeller shaft. Buy using magnets like they did no shaft has to penetrate the sealed motor unit. If either magnet comes loose the pump stops working but the motor will spin.


Hope I made sense with this.

 

[JCKnife]

Yes, DB, that makes sense--thanks! How do you open the top casing? I see no obvious way...

I know there are guys running 100% WMO whereas I have 35 gallons max in there (the rest diesel). So I don't see the viscosity of the WMO overpowering the magnetic pump.

 

[gimpyrobb]

Nah, your pump failed at an in-oppertune time. Its was just a coincidence.

 

[JCKnife]

My new pump from Olympic Controls arrived today. It came complete with BOTH gaskets (the circular 10-hole one for the whole assembly, and the smaller one where the power goes through). Unfortunately I had already ordered a gasket from e-bay but at least I have a spare.

The bottom plate on the new pump is riveted in place to prevent the failure experienced by the OP of this thread.

My old pump runs but does not pump. I never did disassemble it beyond the 4 screws. If anyone wants my old pump they can pay the shipping and have it for free.

 

[Jakob]

Depending on what I find out when I get home, I might take them both.

 

[DieselBob]

How do you open the top casing? I see no obvious way...

Sorry I didn't see your question earlier. The motor housing is sealed so I used a hacksaw to cut the can open. There is no way to open it without destroying the motor can. You up and running now with the new pump ?