777Dave

777Dave

Well Known Member
My Vans fuel valve is seeping slightly just below the handle. Anyone bothered to rebuild one? Assume it’s a matter of replacing O rings or seals….? Don’t suppose Vans has a kit….

Thanks
 
I've got one for you if you need it

Dave, I've got one brand new (albeit 15 years old or more probably) from when I opted for the Andair instead. I'll ship it your way for $20. (Just confirm if you need a 3 or 4 port).
 
Just unscrew the cap and replace the two o-rings.
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Very easy valve to replace those two O-rings. You don’t even have to remove the valve from the plane either, just drain both tanks, remove the handle, and unthread the top cap. Do NOT use fuel lube on the valve unless you are sure you don’t go anywhere cold.. I had mine nearly impossible to turn after cold soaking up at 17,500 feet. I plan to wash it out and maybe try Kryox grease that I bought. Also be careful not to damage the gasket under the cap..

Anybody have an idea where to get a replacement washer that seals the valve? I can’t seem to locate one to have as a spare.
 
Taltruda said:
Very easy valve to replace those two O-rings. You don’t even have to remove the valve from the plane either, just drain both tanks, remove the handle, and unthread the top cap. Do NOT use fuel lube on the valve unless you are sure you don’t go anywhere cold.. I had mine nearly impossible to turn after cold soaking up at 17,500 feet. I plan to wash it out and maybe try Kryox grease that I bought. Also be careful not to damage the gasket under the cap..

Anybody have an idea where to get a replacement washer that seals the valve? I can’t seem to locate one to have as a spare.
Click to expand...

If that ever happens again, you can free the cone by lifting the handle with two fingers under the handle and then turn it.
 
Taltruda said:
I had mine nearly impossible to turn after cold soaking up at 17,500 feet.
Click to expand...

Some time ago mine started becoming nearly impossible to turn. It wasn't due to the cold.. I really don't know why it starting binding. But it sure got my attention! That cheap valve is potentially very dangerous. What if it decided to lock up halfway across when switching tanks when it's in the "OFF" position? Answer: flame out in a matter of seconds.

I opened it and cleaned it and it has worked fine ever since, but I worry about it every time I switch tanks. That valve should NEVER bind or even be of a design that might bind like that.

BTW, be careful if reassembling with lubricant. That lube can squeeze out and clog the fuel lines and/or filters.

The fuel delivery system on these airplanes are their weakest and most vulnerable point of potential failure.
 
71459 said:
Some time ago mine started becoming nearly impossible to turn. It wasn't due to the cold.. I really don't know why it starting binding. But it sure got my attention! That cheap valve is potentially very dangerous. What if it decided to lock up halfway across when switching tanks when it's in the "OFF" position? Answer: flame out in a matter of seconds.

I opened it and cleaned it and it has worked fine ever since, but I worry about it every time I switch tanks. That valve should NEVER bind or even be of a design that might bind like that.

BTW, be careful if reassembling with lubricant. That lube can squeeze out and clog the fuel lines and/or filters.

The fuel delivery system on these airplanes are their weakest and most vulnerable point of potential failure.
Click to expand...

I disagree
The weakest point is the person building, operating, and maintaining them.
All three require some serious thought.

My thought process while operating (flying) is to never move the fuel selector (regardless what brand airplane or fuel valve is involved) in an airplane without first considering what my forced landing options are at that moment.

As for the fuel "system's", accident history has proven that they are extremely reliable.
What accident history actually shows is that likelihood of an accident precipitated by the fuel system design goes way up when a person has a better idea and redesigned it to something better.
 
What are the o-ring numbers?

777Dave said:
My Vans fuel valve is seeping slightly just below the handle. Anyone bothered to rebuild one? Assume it’s a matter of replacing O rings or seals….? Don’t suppose Vans has a kit….

Thanks
Click to expand...

Isn't that the basic question? You can get from Spruce using mil spec o-rings. No kits - liability.

777Dave - there are only two o-rings, EDPM will be fine, 1/16" cross section. The large one is .750" ID 1/16" cross section - 018 number. Nitrile
the small one is .312" ID, and either 1/16" or 3/32" cross section -011 or -109 number. Nitrile

I don't remember what the small o-ring cross section was, but you can measure your valve get both to be sure. 70% it is 1/16"

Clean and lube with Krytox. I just rebuilt one and still on the bench, if you really need the small I will take it apart and measure for you.

Here is the o-ring chart so you can measure and verify yours. This is a super handy chart. Use ID of your application and select closest section.

View attachment O-ring_Size_Chart.pdf
 
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rvbuilder2002 said:
I disagree
The weakest point is the person building, operating, and maintaining them.
All three require some serious thought.

My thought process while operating (flying) is to never move the fuel selector (regardless what brand airplane or fuel valve is involved) in an airplane without first considering what my forced landing options are at that moment.

As for the fuel "system's", accident history has proven that they are extremely reliable.
What accident history actually shows is that likelihood of an accident precipitated by the fuel system design goes way up when a person has a better idea and redesigned it to something better.
Click to expand...

Sure I get that and it's a valid point of view. But by "weak" I mean the fuel system has a lot a delicate failure points. Small, fragile parts. Minute passages that must be kept practically sterile. One or more pumps that must always work. Filters that can not clog. All sorts of pipes and tubing that must be kept cool and free of air gaps. My airplane has a carb - that means my butt depends on a tiny rubber needle valve held in place by a bulb floating in gasoline that I can't check or ever see. If a grain of sand gets in there, the engine could stop running. Good grief.

Compared to the other systems, the least reliable and most trouble-prone system in the airplane is the fuel delivery system. And that's true whether you are a perfectionist maintainer and pilot or not.
 
Van's fuel valve

my fuel valve orings started leaking at about 20 years in my rv .
simple fix and very reliable valve.
my experience,yours may differ.
 
71459 said:
Sure I get that and it's a valid point of view. But by "weak" I mean the fuel system has a lot a delicate failure points. Small, fragile parts. Minute passages that must be kept practically sterile. One or more pumps that must always work. Filters that can not clog. All sorts of pipes and tubing that must be kept cool and free of air gaps. My airplane has a carb - that means my butt depends on a tiny rubber needle valve held in place by a bulb floating in gasoline that I can't check or ever see. If a grain of sand gets in there, the engine could stop running. Good grief.

Compared to the other systems, the least reliable and most trouble-prone system in the airplane is the fuel delivery system. And that's true whether you are a perfectionist maintainer and pilot or not.
Click to expand...

If the standard RV fuel system had a lot of delicate failure points that resulted in failures that influenced engine operation (when compared to other systems in an RV that could cause an accident), there would be statistical evidence to support that.

Statistics of RV accidents with the fuel system being the result of engine stoppage do not support your argument.
A large percentage of the fuel delivery related accidents have been on airplanes that didn't have a built per plans fuel system (often times because the airplane also had an alternative engine installed which automatically means it will have a non-standard fuel system).

If you actually look at the data closely, you will find that engine failure related accidents were most often precipitated by electrical (ignition) or mechanical failures of some type which would indicate that fuel system related failures are not the most common (or most vulnerable) cause.

I don't disagree, that there are some vulnerabilities in an aircraft engine fuel delivery system. That is why proper system design is important... proper filtration of the fuel at the proper locations in the system, etc.
This is no different from the auto industry.
Ground vehicle fuel systems have the same vulnerabilities, which is why they have very specifically designed systems as well, but even those systems will fail to operate properly if proper maintenance is not performed.

A good overview of the cause of accidents in RV's is Ron Wanttaja' article linked below, for those that might be interested

https://www.kitplanes.com/homebuilt-accidents-focus-on-vans/
 
It would be very interesting to look at the contribution of fuel system design to post-impact fire...
Hard lines, battery proximity, gascolator location etc.
Mike
 
rvbuilder2002 said:
If the standard RV fuel system had a lot of delicate failure points that resulted in failures that influenced engine operation (when compared to other systems in an RV that could cause an accident), there would be statistical evidence to support that.

Statistics of RV accidents with the fuel system being the result of engine stoppage do not support your argument.
A large percentage of the fuel delivery related accidents have been on airplanes that didn't have a built per plans fuel system (often times because the airplane also had an alternative engine installed which automatically means it will have a non-standard fuel system).

If you actually look at the data closely, you will find that engine failure related accidents were most often precipitated by electrical (ignition) or mechanical failures of some type which would indicate that fuel system related failures are not the most common (or most vulnerable) cause.

I don't disagree, that there are some vulnerabilities in an aircraft engine fuel delivery system. That is why proper system design is important... proper filtration of the fuel at the proper locations in the system, etc.
This is no different from the auto industry.
Ground vehicle fuel systems have the same vulnerabilities, which is why they have very specifically designed systems as well, but even those systems will fail to operate properly if proper maintenance is not performed.

A good overview of the cause of accidents in RV's is Ron Wanttaja' article linked below, for those that might be interested

https://www.kitplanes.com/homebuilt-accidents-focus-on-vans/
Click to expand...

Coincidentally, Ron just put out an updated article on EAB accidents that was just published by Kitplanes.

https://www.kitplanes.com/homebuilt...pTU8gP6QNcCNFlXf0-e662Q59LrPXI_v0exzbybP_sZGY
 
gasman said:
If that ever happens again, you can free the cone by lifting the handle with two fingers under the handle and then turn it.
Click to expand...

Excellent tip.
Mine just started to get hard to turn. I have been reading this thread hoping for how to lubricant and behold this helpful tip of just lifting on the handle. Worked great, turns like it used to, easy and smooth.
 
I have the o rings and would be happy to send you what you need. Just pm me your address.
 
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