Fuel filler pipe gasket replacement

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

GrantOv

Well-known member
Joined
Feb 5, 2024
Messages
114
Reaction score
43
Location
minnesota
My Car
1972 Mustang Mach1
I found out I have a small gap in my filler pipe gasket going into my fuel tank. Time to replace it! I had hoped to be able to do without dropping the gas tank. I think that dropping it will be necessary due to some adhesive holding the filler pipe at the rear (see picture). Question - (1) how best to dissolve or remove the adhesive (2) what would be signs that replacing the gas tank and components at this time (since I will be dropping it). I think these components are all original based on condition. Thanks! First picture shows from inside the trunk of the filler tube adhesive, Second shows the old gasket and gap that exists (causing fuel leak).
 

Attachments

  • IMG20240316105605.jpg
    IMG20240316105605.jpg
    89.4 KB
  • IMG20240316105611.jpg
    IMG20240316105611.jpg
    175.2 KB
Since you have to drop the tank anyway, just replace it. Your original tank is over 50 years old and is bound to have rust and corrosion inside. A new fuel tank is not expensive. I just bought a new tank for my '72 convertible off eBay for $133 shipped. This is the tank I bought:

https://www.ebay.com/itm/295734796177

While you have the tank out, replace the rubber fuel supply and vapor return hoses and the associated hose clamps. Replace the rubber hose and clamps at the fuel pump inlet, too. I also recommend replacing the vapor return valve and its rubber seal (about $55 from NPD). It might also be a good idea to replace the fuel gauge sending unit. It's probably a rusty mess as well, plus the filter "sock" may have disintegrated. They don't cost much, usually less than $30.

As they say, "Buy once, cry once." Replace it all now and you'll never have to do it again for the rest of your life. The whole job will take one afternoon and cost you less than $250, and when you're finished you'll have a million dollars' worth of peace of mind.

I am about to do this entire job on my Mustang. I am waiting on parts to arrive and for my helper to have some free time. We did this exact same job on my '73 F100 Explorer Special a couple of months ago as well. Its fuel tank was a horribly rusted mess, as was the sending unit. The rubber hoses were leaking fuel, too. They weren't cracked. The fuel was literally seeping through the 51 year old rubber! I shot this photo of the inside of the tank with my cell phone camera. You can see the rust and crud, as well as the fragments of the broken fuel inlet filter "sock".

Fuel tank.jpg
 
Fuel tank replacement.
While there are a few brands offering tanks. I suggest the Spectra Premium F32A tank which is made in Canada and is "terne coated", which is a zinc alloy coating inside and out. This is a premium tank that will last the lifetime of the car. Best price is on RockAuto.
While at it you'll need a new sender unit. The Dorman 692232 is about the best I've found, BUT don't forget, they may need to be adjusted (calibrated).
I think we discussed this previously.
There was some sort of matting between the tank and trunk floor. It seems to be unavailable. I added some small pieces of solid rubber to act as a vibration barrier plus allow some air flow over the top of the tank. The tank vapour system will need to be restored. There is/was some material in the cap. You can replace that with a piece of ss scoring pad or similar. Also been discussed before.
 

Attachments

  • IMG_1105.JPG
    IMG_1105.JPG
    2.9 MB
Last edited:
Thank you all for the good recommendations - all solid points. I visit my project car on the weekends (haha) so I'll start pulling the parts list together for this next weekend!
 
A tip; replace the carriage bolts, washers and nuts that hold the tank straps with galvanized. These would be 3/8" x 3 1/2 or 4" long.

The old bolts may be a bi*ch to remove, spray with a good penetrating oil a day or so ahead of time.
Anything else to help, just ask.
 
I have a tank I installed 20+ years ago, but never saw fuel as the project stalled.

When I restarted the project in tank pumps were available so I did that.

Shipping is expensive, but I will sell for a reasonable price.

It has the vent hat, fuel level and filler ring so it will be ready to go.

PM me if interested and I can figure out shipping/cost
 
Just a quick check - on the filler neck gasket there is a flared or beveled side - should this go 'up' or 'face inward' to the tank?
 
Fuel tank replacement.
While there are a few brands offering tanks. I suggest the Spectra Premium F32A tank which is made in Canada and is "terne coated", which is a zinc alloy coating inside and out. This is a premium tank that will last the lifetime of the car. Best price is on RockAuto.
While at it you'll need a new sender unit. The Dorman 692232 is about the best I've found, BUT don't forget, they may need to be adjusted (calibrated).
I think we discussed this previously.
There was some sort of matting between the tank and trunk floor. It seems to be unavailable. I added some small pieces of solid rubber to act as a vibration barrier plus allow some air flow over the top of the tank. The tank vapour system will need to be restored. There is/was some material in the cap. You can replace that with a piece of ss scoring pad or similar. Also been discussed before.
Reading up on this now. I have the original filler neck and tank straps. I need the tank, and all the other parts including the vapour system, sending unit, gaskets, and inlet rubber. Not sure what direction I will go, the NPD kit is over $500 and doesn't supply the vapour return valve
 
Not sure what to advise other than mentioned in the above posts.
The vapor cap on the tank is taken off your old tank. I don't think there is a replacement 'element', but some have used an SS scrub pad cut to size.
Calibrating a new sending unit in a new empty tank isn't too hard. Add 5 US gallons (19 ltrs) and that ought to read 1/4 tank. If not, use 2 floor jacks to lift the left side high enough to be able to pull the sending unit and tweak the arm. I forget which way was needed with the gauge reading high. It's a bit hit and miss, but worth it as it's the bottom quarter tank that really matters.
Hope that helps.
By the way, NPD sell the Spectra Premium tank for a lot more than Rock Auto, at least when I bought mine it was.
 
Not sure what to advise other than mentioned in the above posts.
The vapor cap on the tank is taken off your old tank. I don't think there is a replacement 'element', but some have used an SS scrub pad cut to size.
Calibrating a new sending unit in a new empty tank isn't too hard. Add 5 US gallons (19 ltrs) and that ought to read 1/4 tank. If not, use 2 floor jacks to lift the left side high enough to be able to pull the sending unit and tweak the arm. I forget which way was needed with the gauge reading high. It's a bit hit and miss, but worth it as it's the bottom quarter tank that really matters.
Hope that helps.
By the way, NPD sell the Spectra Premium tank for a lot more than Rock Auto, at least when I bought mine it was.
72.jpg
Previous owner pitched the tank, and I don't think he pulled off the vapour cap. I'm starting from scratch, so I will check with Mike / motorcity and see if he has some of what I need. Defintely going with the zinc coated tank
 
View attachment 93515
Previous owner pitched the tank, and I don't think he pulled off the vapour cap. I'm starting from scratch, so I will check with Mike / motorcity and see if he has some of what I need. Defintely going with the zinc coated tank
Sounds like a plan. It looks like you'll need a new tail light panel as well. Again, buy the best repop you can get, it always pays off in the end. Good luck moving forward and looking forward to seeing the results.
 
Sounds like a plan. It looks like you'll need a new tail light panel as well. Again, buy the best repop you can get, it always pays off in the end. Good luck moving forward and looking forward to seeing the results.
This tail panel came with the car. Looks solid, but I'm not sure of the quality

Screenshot 2024-09-29 at 10.29.49 AM.png
 
View attachment 93515
Previous owner pitched the tank, and I don't think he pulled off the vapour cap. I'm starting from scratch, so I will check with Mike / motorcity and see if he has some of what I need. Defintely going with the zinc coated tank
I have my original vapor cap if you want it, $15 plus shipping I swapped to EFI and don't need it anymore.
 
Back
Top