View Full Version : Gas Tank Leakage??

12-14-2014, 07:56 AM
As a Studebaker "Newbie" It's been a while since I asked a rather simple question to those that have gone before me.

My 1950 Studebaker Champion Starlight Coupe is now 3 months old to this present owner.

When I took the car to fill the gas tank for the first time, I drove it home and put it in the garage. The next morning, Dear Wife says she smelled gasoline.

Myself, wanted to find the source of her mentioned odor, noticed some gasoline on the garage floor. There was a dripping from the top of the tank but not fully accessible enough to see all I wanted to see. The so-called drip, dripped onto the tailpipe. A bad thing ready to happen??

Please note that I filled the tank up until the auto-nozzle stopped which meant the filler neck had gasoline in it.

Now, for the crux of the matter. Is there an OVERFILL or might I possibly have a leak. I did use the tank drain on the bottom and removed a gallon or so and the dripping stopped.

I'm apprehensive about having too much gasoline in the tank. What say you guru's out there??? Help!!


12-14-2014, 08:06 AM
A couple things come to mind.

1. The hose where the filler neck attaches to the gas tank has become dry rotted and is allowing gasoline to leak out when full.

2. The fuel gauge sender on top of the tank is leaking fuel when the tank is full. (most likely) look in the trunk under the mat and you should see a round inspection cover similar to the one that covers the under floor master cylinder. Pry it up and have a look. Most likely the gasket is bad or someone has used the wrong type screws and gas weeps up around the threads.

Warren Webb
12-14-2014, 11:51 AM
Not on one of my Studes but on my 41 Ford pickup When I first filled the tank I noticed it leaking at the seam between the 2 halves. Lately on one of my Champ tanks I noticed it leaking around the drain plug where the lead a[[ears to have cracked. That location was originally made with just a plug but I like to install a petcock to drain the tank (when I need gas for lawn equipment) & remove any water that may have accumulated.

12-14-2014, 12:08 PM
It is quite common with these tanks that the seam leaks or as someone else posted that the rubber fill hose is bad.
These tanks are hard to find and you can bring it to Gastank Renu to have it sealed.

Robert Kapteyn

12-14-2014, 12:58 PM
My money is on the gasket on the sending unit , they are set down in s recess in the tank and are very common to leak just enough to cause s large gasoline smell in a garage.

Jerry Forrester
12-14-2014, 01:07 PM
The fuel gauge sender on top of the tank is leaking fuel when the tank is full.
Most probable cause.

12-14-2014, 02:40 PM
Glad you folks are discussing this. I have a leaky tank that I am hoping is due to the sender gasket. I almost forgot. Thanks for the reminder.

12-14-2014, 05:55 PM
My experience has been that the large diameter hose connecting the filler neck in the tank and the filler tube to the gas cap is hardened and leaking. Reproductions have been made and all the major Studebaker vendors stock them.

12-14-2014, 06:01 PM
Do you run modern alcohol in your gas, I had to get another tank because pin holes were developing in my 64, got another tank and had it cleaned at a radiator shop, he had to patch that tank also, while i was there i installed a 3/8" gas line.

12-14-2014, 06:30 PM
You realize there is a acess plug in the trunk to get to top of tank.

12-14-2014, 06:37 PM
My reported "leaking" came from the top of the tank. I was able to check the seam between the top and bottom tank halves. It leaked from the top right onto the tailpipe. Thank goodness the car was "cold". Great way to start a bond-fire!!!

I'll check and see if there's an access port under the trunk carpet but as it stands now, trying to see the rubber connector hose from the filler to the tank is virtually impossible, at least for my aged eyes.

One thing that's noticeable in using the Studebaker FORUM, is the numbers of responses and the immediacy of those willing to help or being reminded they or had have a similar problem. Surely not like a couple other FORUMS I use. So many willing and wanting to help!!!


12-14-2014, 07:50 PM
I agree with a couple of others, it's likely the gauge sending unit.

It's originally sealed with a cork gasket that shrinks/deteriorates with age. There are also 5 "wood screws" that hold it in place, with brass/asbestos crush washers. Those washer also fall apart and allow fuel to weep up the screws and out to the top of the tank.

A local friend and mechanic figured out a "fix" years ago and has done it on all of his cars, plus at least a dozen others. He drills and taps the 5 screw holes with a fine thread tap, puts studs into the holes with a nut and lock washer on the inside (small fingers help), and loc-tite to keep them in place. Then place the sending unit over the studs with nuts and washers on the top side. This way you can really tighten the crap out of the nuts without fear of messing anything up, as it's easy to strip the original screws before they tighten enough to actually seal.

It goes without saying that the tank is removed and filled with water before any drilling is done on it.

Just a tip that works flawlessly for him. Hope it can help someone else.

12-14-2014, 09:26 PM
Leaking when full or filling. I had 3 Studebakers with the same symptoms. All 3 turned out to be the rubber conector between the tank and neck. One was my Silverhawk,a Scotsman truck,and a 62 Lark. The Lark was the easiest to fix.

Come to think of it...Son-in-law had the same thing with his 53 Studillac.

ed ellis
12-14-2014, 09:35 PM
If the leak is on top of the tank R&R the gasket. Be sure the metal screws are fastened down and what ever you do USE COPPER WASHERS UNDER THE SCREW HEADS! Don't ask me why copper washers seal better but they do.

12-14-2014, 10:05 PM
Make sure to use SOFT copper washers, some are too hard and will not seal! Found that out the hard way. Jim

12-14-2014, 10:06 PM
On my truck, I think I'm going to remove the seat, get the sending unit cover off, and slather a bit of soapy water around my sending unit. Then, see if I can gently blow down the filler neck to see if bubbles result.

The trick will be to make some kind of adapter for blowing into the filler tube. It is tempting to use a shop vac with the hose on the exhaust side. However, even blowing, instead of vacuum side...too risky for a spark. Then there's the air compressor...but, gas tanks, 55 gallon drums, and most steel containers, will rupture at surprising low pressures unless specifically designed for pressurization. Since I'm usually alone when doing such projects, improvising is a routine part of many tasks.

As for Matthew's comments and suggestion...I like the idea of studs instead of screws. Something I would consider if the tank has to be removed. As for the screws originally used by Studebaker, I don't think they are wood screws, but sheet metal screws. Regardless of this little "nit-pic," the comment has merit. If you seal the opening perfectly, and gas is able to weep past the screws, it is still a serious problem.

If I determine that my problem is the sending unit gasket, I think I'll buy a sheet of cork material. There are new cork gasket materials that are impregnated/combined with synthetics supposedly resistant to being attacked by gasoline/ethanol. Also, instead of punching holes for the screws, line the holes up and let the screws thread right through the gasket material for the tightest seal possible.

If this works, I'll let you folks know.

12-14-2014, 10:57 PM
Pre 58 cars had the fuel outlet to the main fuel line as part of the sending unit, and was connected by a flex hose with brass crimped ends. (much like a brake hose in looks)
Also check that line. You may have to adapt a barb fitting and use modern fuel injection rated hoses that will not be effected by alcohol.