1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Need to drop gas tank

Discussion in 'Truck & Equipment Repair' started by drifter79, Oct 13, 2014.

  1. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    I have a 89 GMC motorhome cannot get more than 20 gallons in the tank I did clean and check vent hose was clear. Plus was going to pull hose off of tank but tank is full so I figure must have a bad pickup tube or broken one was wondering how to get the top off the tank with out braking anything looks like I just tap the ring off right? There are three hoses coming off the top so figure one to fuel pump and one to generator is the third one a vent hose. Thanks for any help 20 gallons with a 454 dose not get you very far we call it gas station hopping....


    [​IMG]
     
  2. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,673


    Hammer and screwdriver to spin the lock ring.
     
  3. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,673

    Normally you have supply line, return line and evap line.
     
  4. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    Thanks for reply going to have to try and trace lines and see where they go. I know generator take gas for the tank also..
     
  5. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,295

    Ok I'm a little lost...... How much did the tank use to hold?
    Did the reduction in capacity take time to happen or happen quickly?
    The Vent Hose and pick up tubes wouldn't have anything to do with mow much the tank holds. BTW pickup tubes don't break or go bad, they can get plugged though.

    Say your tank use to hold 40gallons, being a thirsty 454 depending on the type of driving you're doing you can expect to see 5-10mpg and seeing a drop in the gauge is a common thing, some times quickly.

    I think your sending unit is on it's way out and giving you a false reading.
    Tank volume/capacity doesn't change if the tank hasn't been caved in or crushed.

    You can take a electric fuel pump and hook it up to the feed line and start filling jugs to drain the tank, plus if it is full you'll also find out how much can go in the tank.
     
  6. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    Buff, was not sure how to explain tank holds 45 gallons the sending unit did just go out so will fix that when I drop the tank. Runs out of gas and will only take 20 gallons and that is filling up to the gas cap so not sure why this is happening. Mileage around 7 miles per gallon.
     
  7. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,295

    Huh......... got me stumped.:confused:
    As I mentioned before I don't believe the pick up tube is the problem but stranger things have happened...... I'd be interested to hear what you find when you drop the tank.
     
  8. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    Will update when I find the problem Thanks for the reply
     
  9. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    BUFF, here is what I found when I got in there. Motor would pop a little when first starting not any more.
    The hose here in red was gone tested the pump ran good so just added the hose put 20 gallons in it and it ran where before if it had 20 gallons would be out of fuel.

    [​IMG]
     
  10. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,295

    huh.......I've only seen hard lines on in tank pumps......

    Well you go it fixed.:nod:
     
  11. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,973

    How did the missing hose still only allow you to put 20 gallons in a 40 tank
     
  12. Banksy

    Banksy PlowSite Veteran
    Messages: 3,113

    This...X2. :help:

    Maybe he meant he can't run on more than 20 gallons before it dies.
     
  13. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    Hey only telling what worked for me I did not set up the system only fixed what was there. With the hose gone pick up tube only goes half way down in the tank and the pump is pumping to no where just showing what worked for me before if I had 40 gallons in tank would only use top 20 gallons could not pump the lower 20 cause there was no hose connected to the pump.
     
  14. kimber750

    kimber750 PlowSite Veteran
    Messages: 3,673

    I am very curious to how it ran at all if that hose was missing? And where did it go?:confused:


    Glad you got it running again. Thumbs Up
     
  15. BUFF

    BUFF PlowSite Fanatic
    from FR NoCo
    Messages: 7,295

    I'm lost too, but something's are better left unknown...........Thumbs Up
     
  16. drifter79

    drifter79 Member
    from pacific
    Messages: 42

    was laying in bottom of the tank turned to gum had rubber clamps on the pump fell apart when I touched them.
     
  17. Nozzleman

    Nozzleman Senior Member
    Messages: 267

    The fuel line was probably not ethanol compatable and disintigrated.
     
  18. Jeep_thing

    Jeep_thing Member
    Messages: 98

    When the tank was full it sucked fuel through the bottom of the pump, without the pickup screen. However when the fuel level dropped about 4" the pump opening would suck air.
     
  19. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,973

    Huh? .the pump is pushing fuel up through that line that wasn't there. If the tank had any fuel the pump was old faithful I'm there
     
  20. mtnbktrek

    mtnbktrek Senior Member
    from NEPA
    Messages: 144

    Is this plow site???