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Dropping The Midship Fuel Tank on my '89 F250 Gasser

fatherdoug

Tonto Papadapolous
The sending unit quit working last year on the midship tank. I bought the combination fuel pump/sending unit with filter since I only want to do this job once. Some people suggest removing the tank shroud before removing the tank, but I didn't find that was necessary. Since the threads on the tank strap bolts are not rusted, it was not difficult to loosen the threads.

I was hoping the upper bolt was a carriage-type bolt, but it isn't. You have to get a 13mm wrench on the bolt on top, and the nut is a 15mm. I am waiting for help to drop the tank so I can get at the sending unit.

I will post the results later after I get the tank dropped. Putting the tank back in, shouldn't be that hard.
 

fatherdoug

Tonto Papadapolous
Got the tank out without any real issues. I was able to support the tank on a plastic bucket while I disconnected the electrical and fuel lines/vent lines. I didn't realize, however, that the plastic vent line runs down inside the rubber fuel fill hose. I had to disconnect the fill hose at the tank in order to remove the tank.

I pulled the old sending unit/pump and tested both. The pump ran and the sending unit checked okay for ohms, but the brass float was full of gas. Problem solved. Now I have fuel level indication in the front tank. The inside of the metal midship tank was spotless, so somebody previous to me had kept the tank full, which limited the condensation/rust. The lock ring was also easy to get off, and I reused the old lock ring.

The next step is to replace the fuel pump/sending unit in the rear(aft axle) tank. I will test drive the truck tomorrow to see if it solves the stumbling issue or the tank switching issue.
 

Fellro

Moderator
Staff member
On my 88 250, I can take the exhaust apart, so I drop it, then after taking the shroud off, I am able to change the pump without dropping the tank... Rear tank is no way to do without dropping, but I have found if I move the exhaust, which on my truck is easy, I can just sit under the truck and take the pump out.
 

dustybumpers

don't play well w others
MIA for a couple of days. sorry


You need to pull your throttle body off, and check the gasket.

I have found over time this gasket to fail, and cause the backfire you are talking about.
Usually on the 5.8, and 7.5's
 

fatherdoug

Tonto Papadapolous
On my 88 250, I can take the exhaust apart, so I drop it, then after taking the shroud off, I am able to change the pump without dropping the tank... Rear tank is no way to do without dropping, but I have found if I move the exhaust, which on my truck is easy, I can just sit under the truck and take the pump out.

I may try that, since the exhaust needs to be replaced also. Thank you.

MIA for a couple of days. sorry


You need to pull your throttle body off, and check the gasket.

I have found over time this gasket to fail, and cause the backfire you are talking about.
Usually on the 5.8, and 7.5's

Good to know. Thank you.
 

Fellro

Moderator
Staff member
Since you already dropped the front (midship) you did the one I refer. Rear must come down.
 

dustybumpers

don't play well w others
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fatherdoug

Tonto Papadapolous
Drove the truck for 70 miles last night with no major problems. The truck accelerated okay with no stumbling. It also started and idled with no issues. I switched back and forth between tanks several times. Once again, the engine backfired once when switching from the front to rear tank. This happened when I was accelerating and switched tanks.

I have ordered a throttle body gasket and will replace it.

Thank you all for the tech support and ideas.
 

fatherdoug

Tonto Papadapolous
Getting ready to drop the rear tank. I thought I was going to have to drop the hitch receiver, but I don't think so. Both exhaust pipes go around the tank and over to the passenger side, so I won't have to do anything with the exhaust, I hope. I'm going to replace both the fuel pump and the sending unit.
 

dustybumpers

don't play well w others
I have never been so lucky as to get a tank to wiggle out of the frame, and past the hitch. I've pulled a whole bunch of them.


Maybe your truck is somehow different. I hope for your sake anyway, as it really sucks pulling the hitch with the gas tank flopping around in there......

:hammer::wavey:

one thing to do while the tank is out,
Check the fitting on top of the rubber brake hose where the steel brake line goes in ( off the rear)
Now is the time to replace that line if it is in need of repair.
 
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fatherdoug

Tonto Papadapolous
I have never been so lucky as to get a tank to wiggle out of the frame, and past the hitch. I've pulled a whole bunch of them.


Maybe your truck is somehow different. I hope for your sake anyway, as it really sucks pulling the hitch with the gas tank flopping around in there......

:hammer::wavey:

one thing to do while the tank is out,
Check the fitting on top of the rubber brake hose where the steel brake line goes in ( off the rear)
Now is the time to replace that line if it is in need of repair.

That is NOT what I wanted to hear! :D This job will probably have to wait until I can get some help. I did pull all the strap bolts one at a time and chase the threads so they will just thread on with my fingers.

I did notice that brake connection and wondered about that. Thank you, Charlie.
 

dustybumpers

don't play well w others
If your going to change out the tank.......
Bronco's had a 35 gal tank. get the pump, hanger, and fuel gauge assy

You also need to either make your own fuel tank straps, or go to the junkyard and find a Bronco with a skid plate/ tank bracket

You will lose the ability to carry a spare, BUT, if you are pulling a trailer with a 460, that extra fuel comes in handy.......
 

dustybumpers

don't play well w others
BTW, you do know that you can pump the gas out of the tank into 5 gal buckets to make it easier to handle, right?
'smiliedoh'
 

smokey

Hitech hillbilly
Staff member
I agree with Charlie you will probably have to take the hitch off. I removed a few and thought it will squeeze past but alas I ended up dropping the hitch after alot of unsavory words.
 

fatherdoug

Tonto Papadapolous
If your going to change out the tank.......
Bronco's had a 35 gal tank. get the pump, hanger, and fuel gauge assy

You also need to either make your own fuel tank straps, or go to the junkyard and find a Bronco with a skid plate/ tank bracket

You will lose the ability to carry a spare, BUT, if you are pulling a trailer with a 460, that extra fuel comes in handy.......

True.

BTW, you do know that you can pump the gas out of the tank into 5 gal buckets to make it easier to handle, right?
'smiliedoh'

Yes, the tank has a couple of gallons in it.

I agree with Charlie you will probably have to take the hitch off. I removed a few and thought it will squeeze past but alas I ended up dropping the hitch after alot of unsavory words.

I like unsavory words! Thank you, both.
 

dustybumpers

don't play well w others
Good to take the hitch off, and look for cracks anyway
( keep telling yourself that, maybe you'll believe it)

Good time to clean and undercoat places you can't get too

( there went the simple project)
 

Fellro

Moderator
Staff member
The bolts might be stressed, so replace them... ;)

I happen to have a Bronco tank, but have to watch them as well, as some were nt fuel injected so be sure to get one that is... I got the one I have for a diesel so it didn't matter. I did install the 38 gallon aftermarket though. The downside of it is they don't make a sender and pump hanger to go with it. Again, this one was for a diesel, and trying to remember now if it had the big hole for the pump or not. I did have the hitch on, and yes it was a not nice word to deal with. I ended up folding the tank lip down to get clearance. What they do for the straps is simply use pipe spacers and either long bolts or threaded rod. Been up there for several years now... I also undercoated the tank before installing it.
 

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