Fuel Milage. Fuel Tanks - how do you know when you're full

[richard waters]

Emery,
I'll try your tactic the next time you fill up.

I wonder how do you know when the tanks are full. Do you wait
until the gas is all the way to the hose nozzle, or is there another cue?
I find that I can never put in more then about 30 gallons. I've tried to
go very slow at the end like you suggested, but since I don't have any
good cue as to where full is, I probably end up not filling anywhere
near the top. Once I filled it a lot more then normal and I could smell
gas inside the coach (my wife was worried that either we would catch
fire or the coach would never stop smelling like gas)

Richard Waters '76 PB, Troy, MI
- -----------

>
>
> It is sometimes difficult to get a full tank in the GMC because of the tanks
> not venting properly. You are pouring a lot of fuel into the larger fill
> hose and the tanks are trying to vent out a very small hose (either 1/4" or
> 3/8"). You'll find that the gasoline filler nozzle will kick off at about
> 1/2 tank or so. Then you might have to stand there for about 5 or 10 minutes
> coaxing a small amount at a time until your tanks are full.
>
> A few months back I posted a suggestion that works for me. When pulling into
> the gas station, I lower my right air bags. This allows me to get in almost
> a full tank before the nozzle kicks off. I may have to coax in the last 5
> gallons or so. The only drawback is having to pump up the right rear airbags
> before leaving the station. However, this is much, much quicker than the
> time it used to take to fill my tank. By the way, this problem occurred even
> after I had replaced all my hoses going to the gas tanks.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM

 

[richard waters]

Thanks for the good advice!
Richard
- ----

>
> until the gas is all the way to the hose nozzle, or is there another cue?
> I find that I can never put in more then about 30 gallons. I've tried to
> go very slow at the end like you suggested, but since I don't have any
> good cue as to where full is, I probably end up not filling anywhere
> near the top. Once I filled it a lot more then normal and I could smell
> gas inside the coach (my wife was worried that either we would catch
> fire or the coach would never stop smelling like gas)
>
> Richard Waters '76 PB, Troy, MI >>
>
> Richard -- I can tell when its full when I look into the fill pipe and see
> the level about 1 or 2" below the top of the fill pipe. HOWEVER, if you have
> any leaks in either your fill hoses or the hoses going to you fuel pump or
> your vent lines you'll probably be peddling gasoline on top of your tanks.
> This may be what you smell. Another cause of gasoline odors is the charcoal
> canisters (it looks like a small black plastic coffee can) that are mounted
> below the passenger seat. If the canister is cracked or the hose loose you
> will get gas fumes there. Note that the vent line of the front tank (the
> Aux. tank) goes to the top of the rear (main tank) and another vent line goes
> from the main tank to a vapor/liquid separator valve located in the driver's
> side wheel well by the front bogie wheel. From there a vapor line goes to
> the charcoal canister. The separator valve can clog and allow liquid to go
> to the canister. The service manual shows how to service that valve.
>
> I suggest that you try to fill to the top of the filler pipe but while you
> are filling look under both sides of the motorhome to see if there is any
> dripping of gasoline from the area of the tanks or wheel wells. If you see
> dripping stop filling the tanks.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM