Fuel Issue

[sport.pilot]

We own a 2009 Monaco Cayman XL. It "ran out of fuel" with the gauge reading a little over 1/8 of a tank. I figured I should have about 15 gallons left. when I filled up the tank, it only took 59 gallons (it holds 75). I have been told that probably the vertical syphon tube inside the fuel tank is cracked or broken. Apparently they are plastic and vibrate a lot. Breakage or cracking is apparently not uncommon.

I would like to know if the coach has to be put up on a lift to get the tank out to inspect the tube or if it is possible to slide it out from the side. I have had two opinions, and I do not know which is right.

If it will slide out from the side, the mechanic that works out of the place we store the coach can do it (way more convenient and less costly for us). If it has to be put on a lift or a well is needed to go under it, then I will need to take it to my dealer which is not close and will be way more costly. Thanks.

[Yaj]

I made 6-2X12 ramps that go up 8 inches. With the MH up on those I'm sure I could get the fuel tank out. I would use extra blocking and jack stands for safety as the air bags could release while working the tank out. I do use the ramps with out safety stands for greasing and general maintenance as while up on the ramps it can't come down far enough to trap or crush me.

[Gary RVRoamer]

The listed tank capacity is what the tank manufacturer spec'ed it at and is the total volume before installation. It does not allow for the location of the filler tube(s) or fuel pick-ups, both of which decrease the effective amount. The actual usable value is typically less, sometimes much less (as you discovered). The most likely explanation is simply that the pick-up tube is a bit shorter than it really should be. None of them actually go to the bottom of the tank - you don't want to pick up the gunk in the bottom.

[sport.pilot]

That is all well and good, but the manual and the promo sheets do not say that - they just say fuel capacity is 75 gallons. And the sales people say the same thing. It is like saying here is a dozen eggs, and when you open your carton, 4 of them are broken, and when you go back to the store, they say that only 8 out of 12 are usable eggs. It is misleading to say the least. Now if they at least told you that the usable fuel was less than the total capacity of the thank due to design or whatever, then that is different and would allow you to make a better choice. Had that been told to me, I would have said please show me a coach with a larger usable fuel capacity. Thanks for the comment - this topic is way more interesting that I thought it would ever be. I am also amazed at how many people have had this same problem.

[Deucenut]

I know that you don't want to use the gas on the very bottom of the tank as there is of course sediment on the bottom. But, if the tank consistently left 1/8 of a tank or more in there, I would think the gas would start to go bad and the amount of gunk to buildup would be huge. I would say the tube is supposed to go to the bottom. I know in my gas 1/2 ton truck, the fuel pump is inside the tank and actually lubricated by the fuel therefore, it siphons from the bottom of the tank. I am not sure if this is the way yours works or not, but I would think fixing the pickup tube will solve your problems. As far as removal of the tank, I would just measure it and figure out if it will come out without a lift. As someone stated already, blocks will probably work best for you to raise the coach up a bit.

[Gary RVRoamer]

The same thing applies to your water and waste tanks - the number in the brochure is the spec capacity from the supplier, not the measured, usable amount. And the freshwater capacity usually includes the amount in the water heater as well, even though you cannot ever use it at the faucet.