Vehicle & Technical > Discovery
LEAKING LPG!!!
thermidorthelobster:
If it vents again, you should be able to find out fairly easily where it's coming from, as any components around the leak will be cold where the gas is vapourising.
Rossko:
If filling "to the stop" is sometimes half what you expect, there's two obvious thoughts. One the tanks is not filling, or one is not emptying.
If one was filling but not emptying you'd probably splutter to a halt 100 miles earlier than you expected! This isn't mentioned, sooo...
If one was not filling at all from the pump (sometimes) you'd have one tank with liquid and one with vapour only. This can happen when the valve designed to stop filling at the 80% level sticks at the previous fill, and still prevents filling after the tank is empty.
Tip : the 80% valve is just like a ballcock, with a float on an arm. Whack the suspect tank with a mallet and you may just hear the arm drop and bounce on the bottom.
The gauge on the dashboard connects to only one tank, which might be a 'good' one or the troublesome one. So its reading might help interpret your symptoms.
In a correct installation, check valves should prevent cross-feeding between tanks via the supply pipes, so an empty one stays empty. This sounds a possibile clue as it might tie up with the hesitation under acceleration ... vapour getting into the liquid feed pipe from the empty tank whilst the just-filled tank is still cold and not giving a lot of pressure. That problem should go away once the just-filled tank gets to ambient temperature and the LPG pressure rises above the 'empty' tank.
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None of which ties up with an escape of gas!! That's an abnormal problem - you must try to track down the source. As mentioned above each tank has a pressure relief valve - which should NOT vent in any ordinary circumstance. I guess it is possible that you have two issues ... imagine if you have one tank not filling (because the 80% valve is stuck up) and the other over-filling (because the 80% valve is stuck up). The filled tank is brimmed at 100% capacity with cold fuel. You were probably squeezing in as much as you could because after all you expected more to go in? None of it gets used on the journey home so its still at 100% capacity and warming up and expanding... tank vents a spoonfull of liquid later - that becomes litres of smelly gas once it comes out. Sound right?
Failed 80% valves allowing 100% fill are not uncommon, but they don't usually lead to venting - simply because some fuel is usually burnt off immediately by driving away.
Sill tanks are commonly 2 x 36L "water capacity", which should give an 80% fill of around 58L from empty, give or take. I believe a few setups use 2 x 40L tanks, giving around 64L at 80%. I'd bet your fills of either 70L or 40L point to the valves on both tanks playing up.
Replacement valves are cheap really. But replacing them involves dropping the tanks right out, and there is a good chance that the brackets/bolts/unions will be troublesome after some years of roadsalt, and further bracketry and pipework will be needed to restore the system :(
cheers,
Ross Kennedy
JimsMowing:
Thank you for all your responses. Some of them seem to make sense, but either way i think im out of my depth here and need to get in seen by a specialist. The only thing is most of the people i have spoken to dont do my system, as they need the correct diagnostic software for my system.
Boo Hoo!
So my trouble now is to find someone that deals with the one i have. Will keep you posted.
Thanks again.
Geoff
Rossko:
err no diagnostic software or brand-name expertise is needed to look at tank or valve problems!! But I expect their caution is because it MAY be something else and they don't want to send you away without a fix.
cheers,
Ross K
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