Punctured fuel tank
Thread Starter
|
Junior User
Joined: Mar 2013
Posts: 64
Likes: 0
Punctured fuel tank
The rear fuel tank on my 1984 F250 with 6.9L 4wd has developed another leak. It was punctured before after getting in an accident, and I repaired it. I will purchase an aftermarket tank unless someone would suggest otherwise. I am not sure if there is a difference for gas versus diesel when ordering one. Mine has a skid plate sandwiched between it and the mounting straps..I think it is 19 gallon. The side tank was also ruptured previously and have decided not to use it rather than replace it..
I think the fuel pick up/sending unit mounting gasket would be good to replace while doing this also.
My fuel gauge always read incorrectly and would read 1/4 tank but run out of fuel. This is not a big problem unless you don't know this and continue running when level gets low.
Just curious if anyone has replaced a tank and had any helpful insight.
I think the fuel pick up/sending unit mounting gasket would be good to replace while doing this also.
My fuel gauge always read incorrectly and would read 1/4 tank but run out of fuel. This is not a big problem unless you don't know this and continue running when level gets low.
Just curious if anyone has replaced a tank and had any helpful insight.
Fleet Mechanic
Joined: Sep 2016
Posts: 1,519
Likes: 224
From: Nevada
Replace the rear tank with a 38 gallon tank. Order the Spectra F26E. Then you will still have the same fuel capacity
as you did with the 2 19 gallon tanks. Also you can eliminate the fuel switch over valve.
The tank is a direct fit. Think I ordered mine from Rock Auto.
You will have to modify the tank sender. I had a Hot Rod shop cut the rod to the float and weld on a piece to extend
it (I Think) 6 1/2". The tank comes with a bunch of hardware to extend the mounting bolts and a piece of copper tubing
to extend the pick up tube. Use compression fitting to attach the tubes.
I ordered two new sending units. You will have to buy the one that has your ohm`s to get the gauge to read right.
Here is one vendor that sells them and the new shower heads..
https://www.gastankdepot.com/ford-ga...ing-units.html
Looks like 85 - 86 is as far back as they go. Maybe the same ohm reading as yours?
https://www.gastankdepot.com/fmsu6der-diesel-fuel-sending-unit-ford-pickup.html
If your sender is ok you could modify it. Mine were as old as the truck and wanted to start all new.
It isn`t all that bad of a job, just time consuming.
I just installed this tank in my 86 F250 6.9 this past summer, but kept the front tank.
Best to remove the bed to access everything.
Charlie
as you did with the 2 19 gallon tanks. Also you can eliminate the fuel switch over valve.
The tank is a direct fit. Think I ordered mine from Rock Auto.
You will have to modify the tank sender. I had a Hot Rod shop cut the rod to the float and weld on a piece to extend
it (I Think) 6 1/2". The tank comes with a bunch of hardware to extend the mounting bolts and a piece of copper tubing
to extend the pick up tube. Use compression fitting to attach the tubes.
I ordered two new sending units. You will have to buy the one that has your ohm`s to get the gauge to read right.
Here is one vendor that sells them and the new shower heads..
https://www.gastankdepot.com/ford-ga...ing-units.html
Looks like 85 - 86 is as far back as they go. Maybe the same ohm reading as yours?
https://www.gastankdepot.com/fmsu6der-diesel-fuel-sending-unit-ford-pickup.html
If your sender is ok you could modify it. Mine were as old as the truck and wanted to start all new.
It isn`t all that bad of a job, just time consuming.
I just installed this tank in my 86 F250 6.9 this past summer, but kept the front tank.
Best to remove the bed to access everything.
Charlie
Scope Wizard
Joined: May 2019
Posts: 6,530
Likes: 25
Charmalu Tell him about the Cussing on the Bed Removal 
here is his Thread on that tank swap https://www.ford-trucks.com/forums/1...sier-than.html
I'm dreading this job myself as I need to repair both tank senders.
BTW running out of fuel at 1/4 tank is a Classic sign of defective Shower head.
polysulfide fuel tank sealant works great on steel Diesel tanks.
here is his Thread on that tank swap https://www.ford-trucks.com/forums/1...sier-than.html
I'm dreading this job myself as I need to repair both tank senders.
BTW running out of fuel at 1/4 tank is a Classic sign of defective Shower head.
polysulfide fuel tank sealant works great on steel Diesel tanks.
Fleet Mechanic
Joined: Sep 2016
Posts: 1,519
Likes: 224
From: Nevada
Yeah...well ya it did give me fits with the bed bolts. 
I finally ground off the bolt heads, then lifted the bed about 4", then cut them off with a torch between the frame and bed.
Was going to torch the nuts off, but you have the plastic fuel lines inside the frame rail to contend with.
Once that was done, and the 2 fuel fill hoses were disconnected and wire harness, it lifted right off.
Double check as you lift there is always that one little thing you forgot..
Stock bed bolts are NLA from
, the only place I could find them was at LMC Truck. Pricy
2 fronts $65 ea
2 centers $10.95 ea
2 rear $24 ea
Just went with regular bolts/washers and Ny-loc Nuts.
My Wife used the impact gun and I held the nuts from under side with a box wrench, zipped them right down in no time.
Charlie
Note: I see you remembered my thread.
I finally ground off the bolt heads, then lifted the bed about 4", then cut them off with a torch between the frame and bed.
Was going to torch the nuts off, but you have the plastic fuel lines inside the frame rail to contend with.
Once that was done, and the 2 fuel fill hoses were disconnected and wire harness, it lifted right off.
Double check as you lift there is always that one little thing you forgot..
Stock bed bolts are NLA from
, the only place I could find them was at LMC Truck. Pricy2 fronts $65 ea
2 centers $10.95 ea
2 rear $24 ea
Just went with regular bolts/washers and Ny-loc Nuts.
My Wife used the impact gun and I held the nuts from under side with a box wrench, zipped them right down in no time.
Charlie
Note: I see you remembered my thread.
Posting Guru
Joined: May 2015
Posts: 2,036
Likes: 5
I always drop the tanks from the bottom just because of how much of a pita the bed bolts can be.
I use a 3/8" air hose and a 35 gallon drum turned sideways and siphon the fuel out. Then it's just 4 bolts for the skid plate and four for the bands. Really not that bad on the back. The fronts can be too low on a 2wd, some heavy ramps can help here or jack it up and block it up with big wood blocks. I don't like jackstands as most don't have a wide enough footprint.
If you just want one tank you'll be happy with the 38 gallon rear, you can use some 3/8" npt pipe nipples to space down the skid plate and use longer bolts if you want to run it. That was my idea anyways if I ever swapped one in.
I use a 3/8" air hose and a 35 gallon drum turned sideways and siphon the fuel out. Then it's just 4 bolts for the skid plate and four for the bands. Really not that bad on the back. The fronts can be too low on a 2wd, some heavy ramps can help here or jack it up and block it up with big wood blocks. I don't like jackstands as most don't have a wide enough footprint.
If you just want one tank you'll be happy with the 38 gallon rear, you can use some 3/8" npt pipe nipples to space down the skid plate and use longer bolts if you want to run it. That was my idea anyways if I ever swapped one in.
Thread Starter
|
Junior User
Joined: Mar 2013
Posts: 64
Likes: 0
Okay, those are good ideas. Likely don't need large capacity fuel tank unless I want to stock up on lower fuel cost fuel at one time. This is a farm truck and does not get more than 15 miles from home.I removed bed within last two years and replaced with standard bolts when repairing/replacing brake and fuel lines. The bed is beat to pieces and did not matter having a bolt head sticking up, so if necessary can remove it. I think I was able to drop the tank without removing bed the last time when repair was done.
I will research shower head. I can't remember how it works and if it would be wise to change. I don't mind refilling at 1/4 tank. Just repairing to keep it running. I think body will likely give up before the rest quits running. It has had a hard life and when it rolled off across the pasture and hit the oak tree we welded a new front frame section on just to replace the hood, grill, and quarter panel.
Thanks for your thoughts on this.
I will research shower head. I can't remember how it works and if it would be wise to change. I don't mind refilling at 1/4 tank. Just repairing to keep it running. I think body will likely give up before the rest quits running. It has had a hard life and when it rolled off across the pasture and hit the oak tree we welded a new front frame section on just to replace the hood, grill, and quarter panel.
Thanks for your thoughts on this.
Thread Starter
|
Junior User
Joined: Mar 2013
Posts: 64
Likes: 0
The upside & downside of being an antique. No longer requires an Inspection but parts are harder to find. Pulled the bed and removed the tank. The sending unit is much like the tank, having been patched and repaired before. The inlet and outlet lines are both completely loose from the cap. The pickup tube was modified with a piece of fuel line.Considering the possibility of silver soldering tubes in cap to make this useable again.
I think a new tank and sending unit will be my choice. When I looked at gastankdepot.com they do not list sending units for pre 1985. I called and spoke with them and was told they do not sell anything for pre 1985. Does anyone know if 1985 or later can interchange? I think the difference will be the hole diameter for sending unit will not be the same. I wondered about switching to later tank but likely will have trouble with fit and filler hose mismatch.
Looking for sending unit and will find tank to suit as it looks like the sending unit is the part that is hard to find.
I think a new tank and sending unit will be my choice. When I looked at gastankdepot.com they do not list sending units for pre 1985. I called and spoke with them and was told they do not sell anything for pre 1985. Does anyone know if 1985 or later can interchange? I think the difference will be the hole diameter for sending unit will not be the same. I wondered about switching to later tank but likely will have trouble with fit and filler hose mismatch.
Looking for sending unit and will find tank to suit as it looks like the sending unit is the part that is hard to find.
Trending Topics
Posting Guru
Joined: May 2015
Posts: 2,036
Likes: 5
I noticed when I bought my sending unit from trexautoparts it said 85-86 and iirc they didn't offer one for the 83-84 diesel. I honestly haven't been around one to check what the difference is. My trucks an early 85 and I've only worked on its fuel system as well as another early 85 when it comes to bullnose anyways, I know bricknose/obs units have the same footprint just the gauge reads different.
I would love if someone with an 83-84 could post pics or measurements of there sending unit just because I'm curious too
I would love if someone with an 83-84 could post pics or measurements of there sending unit just because I'm curious too
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Posting Guru
Joined: May 2015
Posts: 2,036
Likes: 5
Yeah those are definitely smaller, I've seen that size on some gassers but never had a chance to see an older diesel.
If you upgrade to the newer tank/unit you'll have to change the pigtail/plug too. Not sure on the fuel supply hose.
If you upgrade to the newer tank/unit you'll have to change the pigtail/plug too. Not sure on the fuel supply hose.
Scope Wizard
Joined: May 2019
Posts: 6,530
Likes: 25
looks like the 84 and 85 Senders use a different connector ... the connector in the pictures are the same on the 83
I wonder if that was a Gasser Sender and someone drilled the hole to put the return fitting on it ?
I see spectra has the same sender without the return line, but I didn't see a Spectra for the 84 Diesel only found 85 and up diesel from Spectra....
Still I bet if ya called them they might could help.... I'm not sure what the Resistance range is but I'm thinking 10-75 Ohms.
You could measure your old one and get a good idea of what it should be.
I wonder if that was a Gasser Sender and someone drilled the hole to put the return fitting on it ?
I see spectra has the same sender without the return line, but I didn't see a Spectra for the 84 Diesel only found 85 and up diesel from Spectra....
Still I bet if ya called them they might could help.... I'm not sure what the Resistance range is but I'm thinking 10-75 Ohms.
You could measure your old one and get a good idea of what it should be.
Posting Guru
Joined: May 2015
Posts: 2,036
Likes: 5
looks like the 84 and 85 Senders use a different connector ... the connector in the pictures are the same on the 83
I wonder if that was a Gasser Sender and someone drilled the hole to put the return fitting on it ?
I see spectra has the same sender without the return line, but I didn't see a Spectra for the 84 Diesel only found 85 and up diesel from Spectra....
Still I bet if ya called them they might could help.... I'm not sure what the Resistance range is but I'm thinking 10-75 Ohms.
You could measure your old one and get a good idea of what it should be.
I wonder if that was a Gasser Sender and someone drilled the hole to put the return fitting on it ?
I see spectra has the same sender without the return line, but I didn't see a Spectra for the 84 Diesel only found 85 and up diesel from Spectra....
Still I bet if ya called them they might could help.... I'm not sure what the Resistance range is but I'm thinking 10-75 Ohms.
You could measure your old one and get a good idea of what it should be.