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Andy
Andy, Truck Diagnostic Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1587
Experience:  International trucks, International, Maxxforce and Cummins engines, diagnostic, electrical, Hvac and refrigeration repairs
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I have 2012 international Prostar with MAXXforce. fuel in

Customer Question

I have 2012 international Prostar with MAXXforce. fuel in tanks do not remain equal. here's the history of this gost problem. first it started with driver side fuel tanks blowing fuel overflowing and left(passenger) side tanks draining completely. i took
it to the shop they looked inside driver tanks and found piece of rag piece of t-shirt to be accurate. they drained the tank and removed the garment, and said problem is fixed. i drove the truck 100 miles and my fuel started to go up from half tank to full.
i pulled over and checked tanks this time its my right(passenger tank over flowing. driver side tank getting empty. looked inside tanks its clean nothing in it. we used manual transfer pump from harbor freight to transfer fuel and get home, first time when
we transfer from right to left it went back in just 70 miles but second time when we transferred it remained at right level in both tanks. but now after one day it started doing samething again right side tanks filling up and left tanks getting empty. wha
is wrong ? please need help asap
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Andy replied 1 year ago.

Hi there my name is Andy ! Can we start with the last 8 digits of the vin number please ?

Customer: replied 1 year ago.
VIN#9CN448182
Expert:  Andy replied 1 year ago.

thanks ! Ii will look up your vin

Expert:  Andy replied 1 year ago.

It shows that you have a dual draw fuel system . This means both tanks have exactly two lines each leaving the tanks . If this is correct , then follow these steps :

Expert:  Andy replied 1 year ago.

DESCRIPTION

Troubleshooting for fuel tanks not returning or drawing equally:

STEPS

1. Check both fuel tank vent hoses to confirm they are clean and free of debris.

2. Double check fuel tank vents to confirm they are the high flow vent part number(###) ###-####1 and there is one in each tank.

3. Check and verify that both fuel supply lines are the same length, similar routing, and no tight bends or kinks are present, look closely at fuel lines where they pass through the frame rail and have the heat shield sleeve installed on them.

4. Check and verify that both return fuel lines are the same length, similar routing, and no tight bends or kinks are present, look closely at fuel lines where they pass through frame rail and have the heat shield sleeve installed on them.

5. Check and confirm that both fuel draw tubes have the same internal dimension and are the correct length, draw tubes should be 1" from the bottom of the fuel tank. This can be verified by removing the drain plug on the bottom of the tank that is located directly under the draw tube. Also at this time check for debris in the bottom of the tank or stuck to the bottom of the draw tube.

6. Check and confirm that both return tubes are also the same length, and have the same internal dimension use the same method as was used for checking the draw tubes above.

7. Verify that the Voss fitting adapter in the top of the fuel tank for the return line is a restricted fitting the inside diameter should be 7mm.

8. If restricted fitting is not in return port add restricted fitting part number(###) ###-####1 for 5000 and 9000 models that use pipe thread fittings. For ProStar and TranStar models that utilize o-ring style fittings use restricted fitting part number(###) ###-####1 (not all engines require this fitting but if the fitting is in one tank it needs to be installed in the other as well).

9. Check fuel return tee and make sure fuel from engine return enters tee fitting from center (90deg. fitting turned up) of tee, not from one side or the other of the tee.

10. If all other steps have been taken and fuel is still not drawing or returning equally, replace fuel caps (3 inch) with vented cap part number(###) ###-####1.

Expert:  Andy replied 1 year ago.

Please do not forget to rate my service to you at the end ! Feedback is important and bonus is appreciated . Thank you !

Customer: replied 1 year ago.
ok so this truck has everything factory because it's 2012 and only got 200k miles on it. Everything was good until TA dud PM on this truck.wben this truck shut off on the road due to no fuel in one tank I too the fuel filter off. And there was little piece of hardware about the size of quarter I found it looked like a kinda plug for something but there was no place for such thing so I took it out and saved it. Other things I'll will take fuel lines off and check for debrief tomorrow I believe I got to take side skirts off etc can you give any I instructions on what should I do first according to my situation.
Expert:  Andy replied 1 year ago.

If you don't mind , can you send a photo of this plug so that I could have a look ! It might help ! I'm thinking it might be a check valve inline somewhere that came apart . Which filter housing was this found in ! The primary fuel filter mounted on the frame , or the secondary filter on the engine ? Thanks

Customer: replied 1 year ago.

Yes I will

Expert:  Andy replied 1 year ago.
OK thanks
Customer: replied 1 year ago.

Oops sorry for too any pictures I thought it's not attaching lol

Expert:  Andy replied 1 year ago.

That looks like a check valve that came out of place and went through the line . So your fuel is bleeding back down to the tank on one side is what is happening .

Customer: replied 1 year ago.

So where this part supposed to be? I recovered it from fuel filter and it's big to fit in fuel line and it's small to go on the fuel filter hole.

Expert:  Andy replied 1 year ago.

Let me look into this for you a little further .

Expert:  Andy replied 1 year ago.

Sorry for the delay ! Had a small emergency at home but all good now .

Customer: replied 1 year ago.

So what is it?

Expert:  Andy replied 1 year ago.

Still digging right now. I will send the info as soon as I find it.

Expert:  Andy replied 1 year ago.

Which filter was this found in ? The primary filter mounted on the frame ? or the secondary filter mounted on the engine ?

Expert:  Andy replied 1 year ago.

Are u still there ?

Expert:  Andy replied 1 year ago.

Have you had any issues with the fuel pump? In the manual , it talks about fuel pump failures and how they can sometimes send metal debris back into the low pressure sid of the fuel system . Perhaps this is what we are seeing here .

Customer: replied 1 year ago.

primary the big long one. and no no problem starting or idling it runs as usual nothing change. no startup or rough runniig problem at all.

Expert:  Andy replied 1 year ago.
I think we may need to go through all the lines from the engine to the fuel tanks and disconnect and Blow them clean .particularly the return lines as there are restriction fittings . Likely there is debris plugging up one of them and so more fuel is being returned to one tank than the other and this is what is causing this .
Customer: replied 1 year ago.

I'll be going to truck to work on around 11 CA time. I'll be updating you as I go. Is there anything else I need to verify. Doesn't these lines have Anti-Flow back device somewhere? That'll be a problem blowing these line?

Expert:  Andy replied 1 year ago.
If they do it will be at the t fitting above the tranny .
Customer: replied 1 year ago.

I'm working on it here's the update breather tubed good not blocked blowed air then disconnected return lines on both sides they both returning fuel. Now I'm confuse because this problem isn't consistent it goes n comes back?

Customer: replied 1 year ago.

Now took suction line from tank connector and put it in gallon one by one both side suction lines ducking fuel without problem now what?

Expert:  Andy replied 1 year ago.

What about the two tee fittings above the tranny ? How are they ? Have you blown them out ?

Expert:  Andy replied 1 year ago.

Make sure you are blowing the lines in a manner that you can catch whatever may have been stuck in the lines . Blow them into a bucket or something so that we could catch it and confirm that this was the problem. Blow out as many components as you can.

Customer: replied 1 year ago.

I didn't blow the fuel lines because they are working. Return is consistent in both lines and suction is working too at the moment what u did was took breather tubed off and blow them plus blow the lines fitting on the rank. The T on the ready is impossible to reach I guess without removing tanks. Should I take the fuel line from fuel filter and blow ur back towards the tank direction?

Expert:  Andy replied 1 year ago.
Whatever u can do to make sure they are clean is fine . whether a long reach blow gun tip or something like that.
Customer: replied 1 year ago.

Here's the update I idle the truck for hour or so plus run about 5-10 miles without problem but now when truck got on Highway speed it started doing the same thing over filling the passenger side what now? Truck is about 130 miles from my location near TA should I tell them to change the T fitting etc to get rid of the problem would there be other parts? Inside tanks are good nothing inside

Customer: replied 1 year ago.

Can you list all mechanical or electrical components that control this flow or can affect the flow

Expert:  Andy replied 1 year ago.

I will try and find a fuel flow diagram or more info for you . The left side must be restricted more than it should be causing the right side to return more fuel . ARE YOU CERTAIN YOU HAVE FOLLOWED ALL OF THESE STEPS EXACTLY

Troubleshooting for fuel tanks not returning or drawing equally:


STEPS

1. Check both fuel tank vent hoses to confirm they are clean and free of debris.

2. Double check fuel tank vents to confirm they are the high flow vent part number(###) ###-####1 and there is one in each tank.

3. Check and verify that both fuel supply lines are the same length, similar routing, and no tight bends or kinks are present, look closely at fuel lines where they pass through the frame rail and have the heat shield sleeve installed on them.

4. Check and verify that both return fuel lines are the same length, similar routing, and no tight bends or kinks are present, look closely at fuel lines where they pass through frame rail and have the heat shield sleeve installed on them.

5. Check and confirm that both fuel draw tubes have the same internal dimension and are the correct length, draw tubes should be 1" from the bottom of the fuel tank. This can be verified by removing the drain plug on the bottom of the tank that is located directly under the draw tube. Also at this time check for debris in the bottom of the tank or stuck to the bottom of the draw tube.

6. Check and confirm that both return tubes are also the same length, and have the same internal dimension use the same method as was used for checking the draw tubes above.

7. Verify that the Voss fitting adapter in the top of the fuel tank for the return line is a restricted fitting the inside diameter should be 7mm.

8. If restricted fitting is not in return port add restricted fitting part number(###) ###-####1 for 5000 and 9000 models that use pipe thread fittings. For ProStar and TranStar models that utilize o-ring style fittings use restricted fitting part number(###) ###-####1 (not all engines require this fitting but if the fitting is in one tank it needs to be installed in the other as well).

9. Check fuel return tee and make sure fuel from engine return enters tee fitting from center (90deg. fitting turned up) of tee, not from one side or the other of the tee.

10. If all other steps have been taken and fuel is still not drawing or returning equally, replace fuel caps (3 inch) with vented cap part number(###) ###-####1.

Part numbers can be found on the components in many cases. Please go through all these steps ! This is a troubleshooter for this issue and does not necessarily mean that you have the wrong components on the truck ! It should lead you to the problem .

Customer: replied 1 year ago.

Yes I have followed all but didn't check the T fitting yet because flat idle level fuel flows evenly it only does it when at highway speed. Plus can you do more research if there is an other electric pump that had fuel leveling and drawing duties? And also that Tiny part in the fuel filter assembly

Expert:  Andy replied 1 year ago.

How many fuel lines do you have on each tank ?

There should only be two lines per tank ! Correct ?

Expert:  Andy replied 1 year ago.

If so , then there is no fuel transferring pump on this unit .

Expert:  Andy replied 1 year ago.

It should be 2 lines from each tank . Two tee fittings above the tranny . One tee is for the fuel supply lines to engine and the other tee fitting is for the fuel return .

Customer: replied 1 year ago.

Yes two lines on each return and draw. If there's no fuel transfer pump how do tanks level after truck is off for few hours?

Expert:  Andy replied 1 year ago.

This is why tank vents can't be plugged , have to be exactly the same . Also tank fill caps are not vented at all . If one is vented and the other is not , this will play a part in this problem . If any pressure at all is acted upon the fuel in the tanks , it will push from one into the other. All the steps must be followed exactly as stated

Customer: replied 1 year ago.

Vents are clean and fuel caps are same on both side non vented

Expert:  Andy replied 1 year ago.
what about kinking of lines or obstructions? What about the fittings for the return going into the tanks ? Please pull them out and verify that they are the same and not obstructed .
Customer: replied 1 year ago.

Yes u mentioned before fittings are sane and not obstructed

Expert:  Andy replied 1 year ago.

This is the ones in the tank . Correct ?

Expert:  Andy replied 1 year ago.

Then it seems to me that the only thing left is the t-fittings on the tranny . They can probably be replaced from inside by taking apart the shifter boot .

Customer: replied 1 year ago.

I'll be taking the T fitting out today will update you soon. But only thing that is confusing me is If T fitting is bad why it only overflows tank while on Highway why not while idling?

Expert:  Andy replied 1 year ago.

Not too sure about that but I do know that one return line comes from the engine and connects to the top of the tee . Then the return flow should come out evenly from there out to each tank as long as there is no issues with the vents or fill caps .

Customer: replied 1 year ago.

See now I drove back from 120 Miles fuel level went up I kept driving now I Park the truck without turning it off and fuel started to level. So it's only happening while driving at high speed. Anyways can you send me diagram of fuel flow?

Expert:  Andy replied 1 year ago.
I'll see what I can do . I am currently trying to get a friend out of a mudhole deep in the bush with his brand new 3 day old Ford truck
Customer: replied 1 year ago.

Blew the T fitting by disconnecting the lines under the cab and unplugged lines from the tanks then blew the air

Customer: replied 1 year ago.

Ok I'm on test drive total 11 miles and it's still doing it

Expert:  Andy replied 1 year ago.

Have you replaced the T fittings ?

Also have you ever had any lines replaced in the past ?

Customer: replied 1 year ago.

No didn't replace the T fitting should I? And no truck stuff looks new it's 2012 never any fitting replaced only other thing wrong with this truck is fan is always on 24/7

Customer: replied 1 year ago.

This is getting frustration I don't know what else to do.

Customer: replied 1 year ago.

If you can find the flow and also do research why it happens only at highway speed why not when idling

Expert:  Andy replied 1 year ago.

If you want we can continue this on Skype as soon as I get home from work today and help you with both issues .

Expert:  Andy replied 1 year ago.

I can get the troubleshooting for fan and we can have an audio chat on Skype about fuel issue .

Expert:  Andy replied 1 year ago.

I work days at the shop ! Let me know when you want to proceed . Thanks

Expert:  Andy replied 1 year ago.

I am ready when you are today after work about 5 or 6 pm or Anytime on weekend to continue this

Expert:  Andy replied 1 year ago.

I am ready when you are today after work about 5 or 6 pm or Anytime on weekend to continue this

Expert:  Andy replied 1 year ago.

I am ready when you are today after work about 5 or 6 pm or Anytime on weekend to continue this

Customer: replied 1 year ago.

Hey sorry for the late reply right now what I did is plugged the driver side tank that was getting empty causing right tank to over flow. I plugged the return n suction. Basically operating with only one tank the right side. N it's working I just have to fuel often. So my conclusion is that left tank is getting too much pressure causing return to stop while operating on Highway speed we have to solve that

Expert:  Andy replied 1 year ago.

Ok so the only thing that affects that is the things mentionned above in the troubleshooting for dual draw systems ! Something must have been missed somehow. Try this! disconnect the return lines from the fuel tanks to the return t fitting above the tranny . Make up two lines of the same length and install fittings onto them to be able to connect them to the t fitting. Then run these lines to 5 gallon pails . Then start the truck and run it for a bit watching the pails. The return flow should split evenly into both pails . So both pails should end up with the same amount. If it does , then your problem is with one of the tanks . If it does not flow back evenly into each pail , and one is getting more than the other , then the problem is is the t fitting.

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