bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
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 Posted: Thu Aug 15, 2013 6:22 pm Post subject: |
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gas goes in the filler cap and comes out the exhaust as fumes, that is pretty much the total story.
however the two expanion tanks are used to hold fuel that over flows from the gas tank, which happens with a hot weather, or driving or parking on hills. fumes from the gas tank go thru tubes to a charcoal cannister located in the rear right wheel well, at least on my 1986 van it is there. some vans have the cannister hooked up to the air cleaner, mine was factory set to vent to the road, not the air cleaner. go figure????
the overflow tanks do have a check valve in them.
the system is supposed to be pressure tight. the haynes manual has nice discriptions of most specific variations of this sytem.
the rubber hoses used thruout the system if original will not resist todays fuels, the cloth baided hoses on the over flow tanks are paticularly bad and can weep gas, creating a bad fuel smell when the gas tank is topped off or parked on a hill. if they get wet with gas after a fill up, then you need to replace them.
the only acceptable replacement hose for the expansion tank is 30R9 hose, that is rated for the new fuels, lesser hose will fail. 1/4 inch hose works fine, but you must use a quality hose clamp, remember 30r9 hose, NOT 30R7. then it will last for ever.
the gromments on the expansion tanks for the check valve can leak as can the gromments on the gas tank used for a cross over tube on top of the tank.
many folks sell reseal kits for the gas tank and expansion tanks, the gromments needed provided, Many kits are offered with new hose for the expansion tanks, but many kits do NOT use the correct 30R9 and instead offer stock quality hose, this will not work long term with the new government mandated, more expensive, classic car destroying, lower energy content, oxygenated fuel, thanks to the corn lobby and their whore politicans, this gasoline was forced on us. this has caused many failures in the expansion tank sytem in vangons, and has caused many failure on older cars.
the vanagon gas tank is a major pain in the gass to fix, so many little hoses and tanks and gromments. if you got to do it, do it once, take it all out, replace them all with the best stuff then you wont ever have to deal with it again.
PS my charcoal cannister was blocked by a spider nest in the outlet 9the tube that was vented to the road (actually the tube was shoved into a frame member) the spider nest was removed cuase i could not blow air thru it, so that after i had repaired all the weeping gas lines, my system would not breath any more.
I added a screen to keep the spiders out. if yours is attached to the air cleaner, i doubt spiders will get in, if yours goes to the frame, and ends there, make sure it is clear. |
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