Removing fuel tank / replacing pump questions

HaynStang said:

When dropping the fuel tank, do you leave the fuel filler neck attatched to the tank, or do you leave it attached to the car? If I'm pulling the filler neck and tank in one picece do I need to remove the screws around the filler neck gasket where it meets the quarter panel?

When reinstalling the lock ring for the fuel pump assembly, is there a gasket underneath there that needs to be replaced, or does it need silicone or anything like that?

Anything else that I need to know before I put a new fuel pump in?

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i removed the screws and left the filler neck hanging,screws had to be removed so the filler tube can be moved out of the tank as you lower it..

yes, it has a rubber gasket i just oiled the old one and reinstalled it...it was in good shape, but if you buy a pump with the install kit this gasket will come with the kit if not you can buy the kit separate..


heres the article i used to install mine...click on link below.
http://neptune.spacebears.com/cars/stories/scinpump.html

Here are some useful tips...

I have done the tank removal twice, and the main issues are getting the car up on jack stands and getting the gas out of the tank. DO NOT try to do this job without jack stands. Becoming a pancake is not part of the repair process.

Some 5 gallon paint pails lined with garbage bags are good to hold the gas. The garbage bags provide a clean liner for the pails and keep the loose trash out of the gas so you can reuse it. A piece of 1/2" garden hose stuck down the filler neck will siphon all but a gallon or so of the gas.

Remove the filler neck bolts and put them in a zip bag. Disconnect the supply & return lines by removing the plastic clips from the metal tubing. If you damage the clips, you can get new ones form the auto part store for just a few dollars. I have used tie-wraps, but that is not the best choice. Then you remove the two 9/16" nuts that hold the T bolts to the straps. Put the nuts in the zip bag with the filler bolts. Pull the plastic shield down and away from the tank. Once the tank drops a little bit you can disconnect the wiring for the pump & fuel quantity sender.

The pump assembly comes out by removing a large metal ring that unscrews from the tank. You are supposed to use a brass punch to tap on the ring so that you don't make sparks. Look closely at the rubber O ring gasket when you remove the sender. The pump assembly requires some twisting and turning to get it out the hole.

Look very closely at the electrical wiring. The stock wiring can overheat and melt the insulation. Mine had some really crummy plastic tubing slid over the quick disconnects. If the wires ever got together, there would be sparks inside the fuel tank and no more Mustang. I eliminated the splice in the middle of the wiring and went straight from the pump to the feed through connectors for the wiring. It required some soldering and crimping of new tabs on the wires, but it made a neater job.

Inspect the pump mount to metal tubing bracket. Mine broke and I couldn't get it to solder back together. I drilled a small hole for a machine screw & self locking nut to hold the clamp and bracket together.

The pump is easy to get off the mount but is somewhat difficult to get back it the tank without damaging the sock filter or tearing it on the tank baffle. When you install the metal ring that holds the pump in place, watch out for the gasket O ring. Some RTV may be helpful if the ring is not in excellent condition.

The tank to filler pipe seal is a large rubber grommet. Inspect it for hardening, tears and damage. At $20 from the Ford dealer, it might be a good idea to replace it.

I used a floor jack to help lift the tank back in place. You may find that it is the only time you really can make good use of a helper.

Get a buddy to help hold the tank, its a PITA by youself. Unscrew the filler kneck or you will likely tear the rubber.

Once you get the tank out its a straight forward job, be sure to replace the filter while you are under there.

i just put a 255 lph pump in my car like 2 days ago. like the 14 billionth time i've had to change a fuel pump. it's easy man. there's the 2 straps holding the tank on, apparently, then there's an 8mm bolt holding the filler neck to the tank. you don't need to take the 3 bolts holding the filler neck to the quarter panel off yet. you need to take the 8mm bolt off and the two straps, then lower the tank, being careful not to rip the fuel lines or harness. the filler neck will stay attached to the car. lower the tank enough so you can unhook the fuel pump/sending unit harness and disconnect the fuel lines. after you lower the tank all the way, you can now remove the 3 bolts and take the filler neck off if needed. there is no "gasket" per say, but there is a rubber ring that goes in between the round upper part of the fuel pump bracket and the tank. you don't really need a second person either, just be smarter than a rock and do it when your tank is empty. good luck! oh and btw, it'd be a good time to change your fuel filter too.

fuel pump installs are one of those jobs that are "hard" to alot of people but its actually a pud job on a mustang, two guys can knock it out in an hour or two

I just did a new tank instal In my mustang. Had no issues to report. Went smooth. I installed a 96 tank into my 86 mustang. Actually the 1979-97 tanks will all work in any of those years cars for your information.

Not to threadjack, but are the SN95 tanks of a larger capacity, or are they the same as those in most Foxes? Just curious as to why you'd swap in a newer one, other than if perhaps simply because it was available...?

Darkwriter77 said:

Not to threadjack, but are the SN95 tanks of a larger capacity, or are they the same as those in most Foxes? Just curious as to why you'd swap in a newer one, other than if perhaps simply because it was available...?

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Maybe the old one was rusted out

I would replace the fuel tank gromet. I have had leaky ones before, or it is possible to that you could rip your old one taking it out. They are about 12-14 dollars at the dealership.