Mustang Gas Tank Installation

Mustang Gas Tank Installation is easy and quick with the right safety precautions.

Whether it's a classic Mustang restoration, or a leaky, rusty tank, this is a do it yourself project you can accomplish in a couple of hours or less.

mustang gas tank installation

Gas Tank Removal and Installation Guidelines

If you are starting with an old gas tank that's been empty for a long time, that's great, but what if you need to replace a full or partially empty tank on an early or classic Mustang ?

Follow these steps and you can make a quick and safe job of gas tank replacement.

Tools and Materials:
Basic socket set
crescent wrench
small metal scraper
package of "dum dum" sealant strips
oil change pan or other plastic tub


1. Before you begin your Mustang gas tank installation, place the tub or oil change pan underneath the drain plug, which is located at the back of the gas tank (pointing towards the front of the car).

gas tank drain plug

2. In a well ventilated area away from flames, smokers etc... using the crescent wrench, carefully undo the drain plug and allow the old fuel to drain into the pan. Transfer the fuel into an approved container away from your Mustang.

Note: if you can't dislodge your drain plug, jump to step 3 and drain it after you've removed it from the chassis.

3. Removing the gas tank from your classic Mustang is easy, but if you still have fuel inside, you'll need to support it from below with blocks, wood or other materials. You could use a floor jack, but be very careful because if the fuel inside starts to slosh around, it can roll right off the jack which isn't a situation you want.

gas tank sender location

Begin by removing the fuel gauge sender clip where it's attached to the back of the gas tank sender. With the oil change pan below, remove the fuel line clamp from the gas line. Pull the hose off the metal line and plug the rubber hose with a small bol to keep any remaining fuel in the tank.

4. While it's not absolutely necessary to completely remove your fuel filler tube, it makes your Mustang gas tank installation much simpler. Separating the filler tube from the big rubber connector hose is a real pain, with an immoveable tube. mustang gas filler tube

5. Here's how to remove the tube. Remove the gas cap, by unscrewing it from the filler tube, then taking off the small nut which attaches it to the outside flange of the fuel neck tube.

Using a screwdriver or nut driver remove the two metal clamps that secure the gas tank filler neck to the rubber tube.

6. Remove the other screws/bolts that hold the filler tube to the rear body panel and pull the filler tube out of the rubber connector through the hole in the rear light panel.

7. Remove the gas tank bolts which secure it to the trunk floor. Then carefully pry it away from the sealant strip underneath and lift it up and out of the trunk area. If you are dealing with a fairly full tank of gas, having a friend help can be a big bonus. Gas weights about 10 lbs per gallon, so even wrestling out a half filled 1965 Mustang gas tank means you have some 80 lbs to lift up and out of the trunk area!

mustang gas tank sealer dum dum

8. Scrape off the old "dum dum" strip and lay down a double row of new sealer. This stuff is pretty cheap and is much friendlier to work with than silicone if you ever need to take it out again.

Mustang Gas Tank Installation

Installation is the opposite of removal, but....

Wondering what that one strangely big bolt is and where it goes?

Or maybe your restoration project car came without a gas tank and along with a new gas tank, you picked up a Mustang Gas Tank Installation kit, containing a bunch of shiny new chrome screws and a big black bolt and spring nut.

And if you're wondering why they gave you that bolt, start looking for the bigger hole on the left hand side of the back of the tank. The bolt goes through the tank and not only helps hold the tank to the trunk floor, but also secures the driver's side of your rear valence to body bracket.

installed mustang gas tank in trunk

If you haven't already done it, while you are clipping the fuel tank sender wire back on, you should also replace that little piece of gas line along with some new clips that mate the fuel line to the tank, before you refill it with gas.

Reattach the gas filler neck, gasket and gas cap. Check for leaks. Start you car and check for leaks again. If all checks out, you're good to go !

You're Mustang's tank works fine but looks bad?

Gas Tank Restoration Learn how to restore your classic pony car's gas tank to like new condition in Part 11 1965 Mustang Gas Tank Restoration. (well maybe not new, but it will look good and won't leak)

Part 1 - Mustang Restoration

Part 2 -Resurfacing Minor Irregularities

Part 3 - Rear quarter panel repairs

Part 4 - Inner Fender Refinishing and Repair

Part 5 - Mustang floor pan replacement

Part 6 - Floor Pan Replacement Continued

Part 7 - Headliner Replacement

Part 8 - Mustang Dash Restoration

Part 9 - Trunk rust repair

Part 10 - Priming and Painting your Mustang Part-1

Part 11 - Gas Tank Restoration

Part 12 - Color Sanding

Part 13 - Mustang gas tank Installation

Part 14 - Mustang gas tank Restoration

Return to Ford Mustang

Share this page:
Enjoy this page? Please pay it forward. Here's how...

Would you prefer to share this page with others by linking to it?

  1. Click on the HTML link code below.
  2. Copy and paste it, adding a note of your own, into your blog, a Web page, forums, a blog comment, your Facebook account, or anywhere that someone would find this page valuable.