Need New Fuel Tank Caps

[The_Handier_Man1]

From: SeaRaySRV16O  (Original Message)
Sent: 8/16/2004 9:58 PM

Replaced my fuel caps Saturday because the seals were leaking and allowed fuel to spill out on a hard left turn. Found out immediately that these caps need to be VENTED. The caps I bought at Auto Zone appeared to have a plastic vent in the cap, however pressure built up in both tanks with the new caps and my secondary tank began leaking. Still haven't tracked down the source of the leak. Have two more vented caps on order now from NAPA and hope they will work the way they are suppose to. 



From: 70winnie
Sent: 8/17/2004 6:06 PM

what's the part number on those new fuel caps?  thanx.



From: daved27c
Sent: 8/17/2004 10:34 PM

Robert;

The way to tell if you need vented gas caps or not is simple. If the vehicle is fuel injected, then it needs unvented caps. On modern vehicles The fuel cap is actually a pressure relief valve of sorts. The fuel cell is pressurized under normel use. This is why if you remove the gas cap on your car with the engine running, the "check engine" light will come on. It senses a change in pressure. As far as the Winne, You need plain old vented caps. These were the standard of the industry when carbs were used. By the way, when you overfill a gas tank that has a vented cap, gas will leak out. How full was the tank when you had the leak? You might not need to spend the money on the new caps.

Dave



From: SeaRaySRV16O
Sent: 8/18/2004 10:04 AM

The NAPA/Balkamp pn for the cap is 703-1221. There hasn't been any real hot weather to check and see if this cap's vent is working, but appearance wise it looks like the old caps. The reason I went to new caps in the 1st place was because on a hard left turn fuel would slosh up and out the filler tubes 'cause the seals on the original caps were worn and shrunk and the caps fit loosely. This cap looks to be correct, got a 2nd one ordered cause it's not a common part that NAPA stocked locally.



From: SeaRaySRV16O
Sent: 8/18/2004 10:09 AM

Dave,

The tank was pretty full, maybe 90%, however, the leak was not coming from the filler tube 'n cap area. Haven't gottn underneath to check the source of the leak, but when I took the
unvented caps off the leaking stopped. Also could hear a hissing as the built up vapor pressure released when the cap was loosened. It was a pretty warm day last weekend and that warmed up the fuel and caused the problem IMO.



From: biggrock1
Sent: 8/18/2004 7:42 PM

I certainly don't know about all winnies but mine requires two different types of fuel caps. I found that out when I took the one good one that I had to Napa to get one like it and when I brought it home, it didn't come close to fitting. I had to buy kind of a generic cap and add extra rubber washers for it to seal.



From: nailhead
Sent: 8/20/2004 8:09 PM

I'm not sure what year you're looking for, but a lot of truck stops have some old school caps.  The old chrome ones that screw  two sets of offset tabs down and the ones threaded on the inner ring of the cap are available at Flying J truck stops.  I guess I don't need to replace mine because if I make a hard left, I'm more likely to be acquiring the services of a heavy rescue than NAPA.



From: Plainobob1
Sent: 9/20/2004 6:18 PM

hey sea what year is your winnie and did you get the new ones yet and if so did they fit ?ive got a 77 chieften  and them gas caps r leaking also . have 3 new ones setting right here in front of me now that dont fit lol



From: SeaRaySRV16O
Sent: 2/5/2005 4:27 PM

Hi PlainoBob ...

Sorry I been so remiss in answering. Was drivin' 18-wheelers last year & only got home every 2 weeks. Guess I put the gas cap problem on hold when I parked the Winne for the season and haven't visited the classic site in awhile.

Mine is a '72 w/413. Has dual tanks with the old style vented chrome caps.

The NAPA/Balkamp pn# 703-1221 appear to be vented but are not. I am thinkin i will get a tiny drill size & just vent them myself. Will update if this solves the problem, which is, vapor pressure is forcing fuel outta my secondary tank when the outside temp gets warm. This could be a real fire hazard should it go undetected. A tiny amount of fuel leaking out the filler tubes on hard left turns is not near the problem.



From: denison
Sent: 2/5/2005 10:11 PM

Didnt the auto industry begin using non-vented caps, on all gasoline powered cars and trucks about 1974 or 75, when they began to include vapor recovery canisters? I think thats when the California standards on vapor emissions went into effect. Im pretty sure the federal standards also required them by 1977.



From: SeaRaySRV16O
Sent: 2/6/2005 9:31 PM

I'm thinkn' yer right denison,
That's most likely why there aren't vented caps around anymore. Maybe I outta check out some truck repair shops that work on the old gas powered Dodge trucks.