Gasoline Leak

DW_Gray

DW_Gray

Well-known member
Tonight my neighbor reported to me he smelled gasoline near my RV. I went out to check and sure enough, there was gasoline on the pavement under the tank. What I guess to be a rubber vent pipe was wet with gas and there was a large spot on the pavement. I then removed the gas cap and pressure was released and about a pint of gas was forced out. I replaced the cap. Then I washed everything down with water.

I topped off the tank last week for the first time but today was the first notice of a leak. Today was warm and I suspect that caused the tank to pressurize. I read some of the other threads and it appears my tank may be over filled.

Do you have any other ideas?
 
truknutt

truknutt

Committed Member
DW,

Have you checked your vent on the tank to make sure it's not blocked or pinched? When I overfilled the tank the first time (to see what the true capacity was) the overlow came out the vent. You state that pressure was released when you removed the cap. With a vent there should be no pressure build up.
 
DW_Gray

DW_Gray

Well-known member
truknutt said:
DW,

Have you checked your vent on the tank to make sure it's not blocked or pinched? When I overfilled the tank the first time (to see what the true capacity was) the overflow came out the vent. You state that pressure was released when you removed the cap. With a vent there should be no pressure build up.
Click to expand...

Good point. I'll check the vent first thing in the morning. Thanks.
 
DW_Gray

DW_Gray

Well-known member
OK, I checked the vent hose and there does not seem to be an obstruction. But when I opened the gas cap, there was air pressure again. Another warm day. I'm glad it's not hot.

Is there a simple way for me to test the fitting on top of the gas tank that the vent hose is attached to? Is that some type pressure valve? It's not an easy place to get to.
 
DW_Gray

DW_Gray

Well-known member
Well this problem resurfaced today, but worse. Today after returning from the Grand Canyon, as soon as we walked in there was a strong odor of gasoline. It was a lot stronger in the garage. I checked outside below the fuel tank and notice that some gas came out the vent pipe hanging down. I open the gas cap and a little bit of fuel came out and it's full to the filling rim. I added some fuel just before weigh-in at the Rally in Nashville. But I didn't over fill it. Right now the fuel gauge indicates it's only 7/8 full. The air is better in the living area but the garage is very bad. I've got the windows open and the fan on.

I don't know what to do next so any ideas will be helpful. What I don't understand is we have been in conditions hotter than this in recent days and there were no problems.
 
jmgratz

jmgratz

Original Owners Club Member
Gasoline will expand in as the temperature increases. Is it possible it overflowed due to the expansion? Be very careful because gasoline fumes are very explosive. Ventilate throughly.
 
porthole

porthole

Retired
Make sure all your hose clamps are tight. The tank shouldn't be vented to the atmosphere, EPA regs changed all that. You might have the tank overfilled. How much gas did you put in?
IIRC the tank is a 30 gallon size with a 28 gallon capacity (room for expansion).
I have never got more then 23 gallons in mine.
 
DW_Gray

DW_Gray

Well-known member
I read that my tank is 27 gallons. The higher elevation did cross my mind but I didn't know if that would affect the tank. I only added enough gas to bring the needle to near the full line. I already knew not to overfill it. What's odd is that I haven't used the generator since then yet the gauge now shows the tank is 7/8 full. It's just weird.

The original time I had this problem I was near sea level and I assumed I overfilled it.
 
R

Recovered from 25-May-2010

Recovered
Dave,

My in-house Chemical Engineer (Nancy), spouted off the formula for expansion of a liquid based on pressure change. It was all Greek to me though. Not saying this was the issue, but if your tank was full, the elevation change, and therefore the pressure change (lower pressure) would cause some expansion of the gasoline.

Let us know when you get back down to say 1000' or lower, if the gas is still at the rim of the fill port.

Jim
 
porthole

porthole

Retired
Dave, remember your "guage" is just an "indicator". It may indicate that a full tank is only 7/8's full or indicate that a 7/8's full tank is "full".
In my former career in the automotive field within 10% was considered good in the accuracy department.

And think of that "10%" both ways for a 20% swing.
 
DW_Gray

DW_Gray

Well-known member
This morning before I left Williams, AZ the expansion was gone. I could not see any fuel in the fill hole. I thought about lighting a match to see better but Amy would not give me the matches. The gauge is still the same. I'm in Riverside, CA now and I just checked it and all is well. I guess there is combination of heat and altitude that plays with this.

So I guess the bottom line is to keep the tank less than full.

I wonder if the later model fuel systems have been modified and what did they do? Can it be done to mine?
 
J

jbeletti

Well-known member
Good report David - thanks. Tell Amy she done good by hiding the matches from the pyro :) Hope all goes well in CA.
 
F

flameon

Active Member
We've had the same problem with gas coming out the past the gas cap while driving and having the people in the cars passing by waving at us pointing at the trailer saying the gas was leaking out of the filler neck,(the gas cap on tight). Some where on this forum there was a note about getting a gas cap (part #35071) at Car Quest, but unfortunatley there is none in British Columbia. Have tried to double seal the gas cap but can't get it on tight enough before the cap starts clicking? The threaded filler neck almost looks like it protrudes out past the end of the filler tube, don't know if that's possible but maybe thats why the cap won't tighten? This happens whether it's full or we've been using the trailer/gen set and also filling the quad up for the weekend runs.
 
wdk450

wdk450

Well-known member
Dave:
This is starting to sound serious enough that I would get Heartland service involved ASAP. If you were in the military, I think you know that the biggest (non-nuclear) bomb in the Air Force arsenal uses gasoline vapor as an explosive.
 
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