# Allis Chalmers 5040 Injection Pump



## DragonflyGrit (Jul 24, 2017)

I have an Allis Chalmers 5040(diesel) that keeps shutting off after 30 minutes of running. If it were the injector pump wouldn't it just quit running altogether and not crank up at all? To date, I have replaced the fuel pump, filters, and hoses.
Thank you for any help and or suggestions.
DragonflyGrit


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## BigT (Sep 15, 2014)

Howdy DragonflyGrit, welcome to the tractor forum.

Please wait for the pumpguy to show up. He is an expert on injection pumps and systems. In the meantime, below is my two cents FWIW.

IMO, your problem is not with the injection pump. You have an obstruction somewhere in your fuel system. It may be as simple as a plugged vent in the fuel tank cap. Loosen the cap and see if it runs OK. 

It may also be a plugged fuel return line from the injectors back to the fuel tank.

Blow the lines out with air. Remove the fuel tank cap before blowing into the tank to avoid rupturing the tank. Do not blow into the injection pump.


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## DragonflyGrit (Jul 24, 2017)

BigT said:


> Howdy DragonflyGrit, welcome to the tractor forum.
> 
> Please wait for the pumpguy to show up. He is an expert on injection pumps and systems. In the meantime, below is my two cents FWIW.
> 
> ...


 Thank you BigT for the warm welcome and I will try your suggestions. It will probably be tomorrow before I get the chance but will let you know how it goes.
DragonflyGrit


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## thepumpguysc (Jan 25, 2015)

YUP.. floaters in the tank or clogged vent in the cap.. BIG T was paying attention in class.. Good call BT & thanks for the plug..
The old 5040's didn't have "safety switches" like we have NOW.. 
IT MIGHT have a filter screen in the shut-off valve at the bottom of the tank, I honestly don't know.. an air hoes & a couple of wrenches should get ya going..


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## DragonflyGrit (Jul 24, 2017)

thepumpguysc said:


> YUP.. floaters in the tank or clogged vent in the cap.. BIG T was paying attention in class.. Good call BT & thanks for the plug..
> The old 5040's didn't have "safety switches" like we have NOW..
> IT MIGHT have a filter screen in the shut-off valve at the bottom of the tank, I honestly don't know.. an air hoes & a couple of wrenches should get ya going..


Thank y'all very much for trying. My father passed away and we are moving all at the same time so I will have to put this on the back burner for a while. I appreciate y'alls help and will let you know what happens when I can start working on it again.


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## DragonflyGrit (Jul 24, 2017)

I'm back and have had time to do some motor work where I'm at so far: It's getting fuel to the injector pump but it's not going any further than that. It's not injecting


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## thepumpguysc (Jan 25, 2015)

Well that sux.. the only thing you can do is remove the top cover on the pump & see if the metering valve is stuck.. Just google> CAV top cover leak.. lots of videos on it..
Its easier than writing out the instructions..
IF the MV is free, you have stuck pumping plungers inside the pump.. not awhole lot YOU can do, other than tear it down & clean it up.. BUT I DONT SUGGEST IT..
I'm in South Carolina & rebuild them for a living & moonlite on the web to help forks out.. IF you like, send me the pump & we'll work something out.. My email is> thepumpguysc at aol dot com


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## DragonflyGrit (Jul 24, 2017)

Okay, I found the problem, the shut-off bar is broke. Is there any way to get just the bar without having to buy the whole injector pump and if so where?


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## DragonflyGrit (Jul 24, 2017)

thepumpguysc said:


> Well that sux.. the only thing you can do is remove the top cover on the pump & see if the metering valve is stuck.. Just google> CAV top cover leak.. lots of videos on it..
> Its easier than writing out the instructions..
> IF the MV is free, you have stuck pumping plungers inside the pump.. not awhole lot YOU can do, other than tear it down & clean it up.. BUT I DONT SUGGEST IT..
> I'm in South Carolina & rebuild them for a living & moonlite on the web to help forks out.. IF you like, send me the pump & we'll work something out.. My email is> thepumpguysc at aol dot com


Ty for your help. The shut-off bar is broke and I'm trying to find one without having to buy an injector pump.
DragonFlyGrit


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## thepumpguysc (Jan 25, 2015)

Sure.. I'll send you one.. send me your mailing address at MY address..
Just put> at a o l dot com after my screen name..
IT IS a CAV DPA pump, right?? & you took the top cover off to find it..?


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## DragonflyGrit (Jul 24, 2017)

Bought a new injector pump and that didn't fix my problem, back to the drawing board


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## thepumpguysc (Jan 25, 2015)

The last update we got was, fuel TO the inj. pump, none out, broken shut-off bar..
IF you got A NEW PUMP.. there shouldn't be a problem getting fuel out, unless the guts are stuck.?? That happens sometimes if they've been sitting on the shelf for awhile.


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## DragonflyGrit (Jul 24, 2017)

Okay, I have my tractor running without it cutting off, but my injector pump is pumping to much fuel. How do I turn it down?


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## DragonflyGrit (Jul 24, 2017)

thepumpguysc said:


> The last update we got was, fuel TO the inj. pump, none out, broken shut-off bar..
> IF you got A NEW PUMP.. there shouldn't be a problem getting fuel out, unless the guts are stuck.?? That happens sometimes if they've been sitting on the shelf for awhile.


TY for your help. The new pump is pumping to much fuel, how do I turn it down?


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## thepumpguysc (Jan 25, 2015)

you NEVER told us what pump you have.. How about some pump #'s..


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## DragonflyGrit (Jul 24, 2017)

I'm sorry. My pump number is: CAV3832F051-U445. For those who may be having the same problem, a rusty gas tank filling the screen at the bottom is what caused my problem.


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## DragonflyGrit (Jul 24, 2017)

I'm sorry. My pump number is: CAV3832F051-U445. For those who may be having the same problem, a rusty gas tank filling the screen at the bottom is what caused my problem.


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## DragonflyGrit (Jul 24, 2017)

UPDATE: Since my last post we ended up replacing the fuel pump with an electric fuel pump and she is running like a champ. It's nice being able to work and get things done again. Thank you all for your help and the time you took from your busy days to help. You are each appreciated so much.


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