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wjbusguy
Active Member
United States
42 Posts |
 Posted - 01/26/2016 : 2:41:02 PM
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Got kind of a strange one here. 2010 IC bus with the DT motor. It quit yesterday on a route, fuel filter light came on and it ran out of fuel and died. I took a filter with me and pulled the old one and it looked fine but I swapped a new one in then I noticed the primer button was sucked in all the way and wouldnt work. I could pull it out and it would slowly pull itself back in like it had a vacuum on it. I went back and took the fuel cap off and no vacuum in the tank. I started unscrewing the little prescreen filter and as soon as the o-ring seal on it came above the housing I heard this little sucking noise and the primer button popped out and started working normal. The fuel system primed up like it is supposed to and the bus ran fine back to the shop. Apparently the section of the fuel system from the primer button to the pickup tube in the tank was plugged off and had been sucked into a vacuum. I have heard rumors that this vintage of bus can have a baffle in the tank that can come loose and can get sucked up against the pickup tube and temporarily plug the line off but this thing held that vacuum for probably thirty minutes till I unscrewed the screen and relieved it. If it was that baffle, I cant imagine that it would hold a vacuum that long. If it was a piece of ice or debris, thats still a long time for it to hold a vacuum. Anybody ran into an issue like this before?
Mike |
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aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/26/2016 : 3:43:47 PM
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| Does this bus have the mechanical fuel pump or electric? We have some 2010s that are 2007 EPA engines and still have the mechanical fuel pump. There is a check valve inside the fuel pump that comes apart and can cause problems. Typically it comes apart and sends debris into the fuel filter housing, but maybe a possibility that a piece got lodged in there somehow and it held a vacuum on it. Might be a stretch, but might be worth checking. |
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mastertech
Advanced Member
274 Posts |
Posted - 01/26/2016 : 5:10:36 PM
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| Yep its hard to believe a broken plate can get sucked up against the pickup tube but we had it a couple times. A couple of small cuts in end of the pickup tube fixes the issue as you cannot remove the broken baffles. Its pretty hard to see the baffles laying on the bottom of the tank as well but if you reach down with a magnet you can pick them up and move them around. |
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slippert
Top Member
USA
630 Posts |
Posted - 01/27/2016 : 05:29:20 AM
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I assume you are in a warm climate? sounds like fuel gelled or water froze in between tank and engine here in Northern state....Can be winter/January issue here...
You might also check to see how much of the zinc coating is gone from your filler neck on fuel tank, IC has been zinc coating inside of filler neck since 2008ish... I have seen the main fuel line completly plugged with that coating at the rock trap/fuel heater/electric fuel pump area, after it came off filler neck... Also pulled out large enough pieces to lay flat across fuel heater and stop flow of fuel... This seemed to be more of an issue with my DT's that have the electric fuel pump... IC recomends pulling filler neck and removing zinc coating to keep from having an issue, doesn't make sence to me,but they are still using the same coating inside of filler neck on my new busses... job security for bus mechanics?? |
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wjbusguy
Active Member
United States
42 Posts |
Posted - 01/27/2016 : 06:47:58 AM
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| Thanks for the replys guys! Yes the bus has a mechanical fuel pump. I am located in southeast Idaho so we are in winter here. I havent seen any flakes or debris in the filter housing when Ive changed filters on any of our buses. I have a nice filter on the dispenser pump so the fuel from the tank should be pretty clean before it gets to the buses. The more I think about it I am leaning toward the baffle sucking up to the pickup tube scenario. If it was ice I dont think it would have gone away instantly like this did where the baffle would have. I havent messed with the pickup tubes before, can they be pulled through the access plate in the floor where you would get to a sending unit? Changed a few sending units out on late 90's bluebirds but never messed with an IC sender yet. |
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RonF
Top Member
867 Posts |
Posted - 01/27/2016 : 08:02:38 AM
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| You might want to check for jelling of the fuel or break down if there is any bio-diesel in it. |
US Army retired CMBT |
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exmod110
Senior Member
150 Posts |
Posted - 01/27/2016 : 08:34:13 AM
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| I just changed the filter housing on the same year of bus, there were pieces of... spring, brass some other material and plastic. looked like a check valve or something let go, this is fairly common failure from what I have heard in my neck of the woods. It had one complaint of fuel filter light with a low fuel press code then a no start with no fuel in the filter housing, fuel was not gelled and lines not blocked or restricted. |
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aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/27/2016 : 08:58:26 AM
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| Exmod110 does that bus have a mechanical fuel pump? If so, read my reply above. |
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exmod110
Senior Member
150 Posts |
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aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/27/2016 : 10:44:27 AM
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| Judging by the size of the smaller spring, it is the check valve inside the mechanical fuel pump. I've never seen brass bits in there, mine have always been plastic pieces and the spring. I don't know for sure if there are any other check valve assemblies in the fuel filter header that could come apart. |
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exmod110
Senior Member
150 Posts |
Posted - 01/27/2016 : 11:19:36 AM
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the brass was in the primer and never made it to the filter side..
It is running well atm but if it has any other issues I will look closely at the fuel pump. Unfortunately it is the only on of that year I have so I have nothing to compare it to. I guess the fix is a new fuel pump as the pumps are not serviceable? |
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aaronwilmoth80911
Top Member
538 Posts |
Posted - 01/27/2016 : 11:37:24 AM
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| Correct. The new pumps look to have a slightly different design to them, so maybe an upgrade of sorts. But, this is IC, so it's doubtful. |
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2010 IC bus fuel issue
