Tripac APU stalling / fuel pump failure

Discussion in 'Auxiliary Power Units (APU's)' started by mndriver, Aug 9, 2017.

  1. mndriver

    mndriver curmudgeon extraordinare Staff Member Supporter

    Had issues last year with the fuel pump failing on my APU. I replaced it with a Mr Gasket 12D from Parts City locally.

    In February this year, it failed again, but this time in Colorado so I replaced it with another one from O'Reilly's.

    And in July it failed again. ????WTH????

    Last week I tried to run the APU for the A/C and it would stall out.

    Tested the system, it had the bad fuel pump again. OK, call the parts guy, ask for a new/different pump. He got me one in. No issues.

    installed new pump.

    engine still stalls out.

    Replaced the fuel filter.

    Still stalls out.


    So I sat down last night with a cigar, cream soda with rum and watched the dog run around the yard while staring at the truck for a couple hours.

    decided I was going to pull out the fuel pickup tube and see if there's a screen or something that's on the end and plugged up.

    This morning I went and looked at the installation manual. Doesn't show a pick up screen, just 2" off the bottom and open tip.

    So instead of taking it all apart and looking, I just pulled the fuel line off the inlet side of the pump and blew air back into the tank for about a minute.

    Put it all back together, started the A/C and.....

    It runs fine now.

    I suspect that a piece of debris or something got into the pickup and it was causing the pumps to work so hard, it burned them out. It was also causing a starvation issue with the engine under heavy load.
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  2. GAnthony

    GAnthony Well-Known Member

  3. mndriver

    mndriver curmudgeon extraordinare Staff Member Supporter

    There's already an inline filter.
  4. GAnthony

    GAnthony Well-Known Member

    ok, but would an in-tank screen filter like i linked you too, be of any more help by having a round pickup?

    even an old fashion sock filter, jerri-rigged in some way with hose clamps and maybe piece of copper or steel tubing inserted into the hose for support to the clamp.
    Last edited: Aug 9, 2017
  5. mndriver

    mndriver curmudgeon extraordinare Staff Member Supporter

    No clue
  6. Mike

    Mike Well-Known Member Staff Member

    Dude, you will do anything to sit at home with the truck, rather than go out and drive it ;)
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    • Agree Agree x 1
  7. CMT

    CMT Well-Known Member

    Glad your persistence worked. I had problems a few years back with mine..same exact unit & would only experience issues in Colorado. Not sure if it was an elevation thing or what. Never knew what the ultimate diagnosis was since I switched trucks shortly after that.
  8. mndriver

    mndriver curmudgeon extraordinare Staff Member Supporter

    I go to Fargo Monday for them fix a 1 gal / 1000 mile leak.

    Yesterday was my annual cardiologist appointment. Friday is my dot physical.

    And most importantly, my youngest is with me this week.
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