View Full Version : Le Mans fuel cap overflow drain hole on a 289
My Le Mans filler cap has a small drain hole for overflow. I plugged it for now so it doesn't drain into the trunk. Requires very careful filling and in my experience there often is too much ambient noise with cars driving past or trucks, etc to easily hear the fuel going in and estimating the level so it doesn't splash out. I have tried leaving the ignition on to see the fuel gauge, but that isn't ideal. Have any of you devised a clever drain tube for that fuel cap overflow hole allowing the spills to run out to avoid the trunk. Looking for suggestions. Thanks.
Derald Rice
04-26-2025, 08:05 PM
How about visiting your local home Depot and seeing if a wax ring from a toilet might be an acceptable sealing ring?
It would certainly be able to conform to non aligning surfaces..
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I have no idea if it would be safe with gasoline
F500guy
04-27-2025, 09:25 PM
Possible to tap 1/8 NPT and put a barb fitting and a hose routed out of the trunk. Not sure about the 289 layout so only a suggestion
Good suggestions, thanks. I did check the diameter and a 3/16" OD fitting will work. Looking for some kind of threaded flange, or barbed drain, but low profile so most of the gas goes down it. The search is on.......meanwhile lots of fun driving around. I may end up drilling down through a 3/16" bolt and then fit up a hose to it. Has no pressure being a drain so snug the tube on and be done.
John289
05-01-2025, 06:46 AM
It is crazy how slow I have to put gas in due to all the bends in the filler tube. But luckily I’ve only splashed over once. I also have the open hole to the trunk. I guess an added benefit is the extra gas we can put in because of the increased tube length. I’ll be interested in your solution.
So I wound up buying a hollow bolt as I broke drill bits trying to hollow out existing ones. I got some M5x16mm hollow bolts on Amazon and some 3mm ID rubber tubing (4mm might be a better option......live and learn) and cut a groove using a hacksaw across the bolt head to lower the drain level (also made installation easier as I could use a screw driver to hold it while I snugged up the nut underneath) and ran the tubing along the fuel filler line.
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Haven't yet filled the tank so I can't say it's field tested. Hopefully this will work. If not I'll try another option.
rpard508
05-11-2025, 06:09 AM
It is crazy how slow I have to put gas in due to all the bends in the filler tube. But luckily I’ve only splashed over once. I also have the open hole to the trunk. I guess an added benefit is the extra gas we can put in because of the increased tube length. I’ll be interested in your solution.
John, I initially plugged the hole with a self tapping screw and O-ring, but eventually I replaced it with a piece of left-over 3/16 CuNi brake line with a flare on one end. Attached some tubing to it and glued it in with JB Weld.213653213653