So been fighting issues with my new rear tank leaking (currently from the sender) and frankly Im tired of messing with it so just going to bite the bullet and buy another one. However figure if Im going to do it might as well go bigger (didn't originally to preserve spare tire). For the 38gal rear tank that LMC sells what all would be required to fit it to a 91 F250? (only lists it fitting up to an 89) figure Ill start new with everything related to the rear tank so Im guessing Ill need the 87-89 fuel tank, a mounting kit and an 87-89 fuel sender?

TLDR - what all does it take to swap LMCs 38 gal rear tank in a 91 F250 4X4

 

I'm pretty sure a 91 is the same as an 89 - they changed things in 92 or so. I've got an 88 F250, and a 91?92? F350, and they are pretty much identical, especially tank wise.

 

That tank that LMC carries is not a diesel tank.

 

Exactly.... That tank is boy rated for diesel fuel

 

Did you lube up the seal on the sender? They "can" leak if you don't. Petroleum jelly is recomended. But I use grease also.

 

What is the difference between a gas and a diesel tank? I remember hearing something about the incompatibility of diesel fuel and certain galvanized coatings, but couldn't get a definitive answer on what to avoid with diesel. I know Racin' and others have used a 32 gallon Bronco tank though... not sure if an LMC Bronco tank would have the same issue. I was eyeing that 38 gallon tank also... so if it's not good for diesel fuel that's good to know.

 

That was it. There's another thread on this somewhere recently where a member called LMC and asked them specifically and LMC said no, the 38 gallon tank is not compatible with diesel.

That being said there are other member here that have been running gasser tanks with no issues.

 

Ya everything Ive read says 89 and 91 have the same tank but every source Ive ever seen has the 89 cut off for tanks and having never compared the 2 I cant say for sure. As far as gas vs diesel the only definitive answer Ive gotten is EVAP equipment for gassers and maybe galvanizing but Ive heard just as many for each side of the galvanizing (for every 1 that says don't, there's 1 running one without problems)

 

I know the factory ford tanks are fine for diesel, the galvanizing isnt Zinc IIRC, its something else. My last tanks were the 351 tanks, and they were fine, Im going to be running this bronco tank, and im not worried at all

 

I swear I've said this a dozen times on here... First, galvanizing means zinc plating. So if something is galvanized, its zinc plated.

Most tanks these days are NiTerne coated. Which is a nickel-lead plating process. I know Spectre makes their tanks this way. NiTerne is diesel and gas safe.

Calling LMC doesn't really prove anything. Who know who you talked to, and what they know. I'd bet they just read what the application was and since it was labeled for gas engines only, they said it won't work for a diesel. This is just like going into a store and asking for the bigger powerstroke oil filter. Its listed to fit powerstrokes, not IDI's so the guy behind the counter will tell you it doesn't fit because he's clueless except for what the book(computer) lists as applications. We all know it will work because someone tried it, and found it physically fits. Same thing for the 3g alternators, they need some wiring work, but the right one will bolt on and work. Soooo call up LMC and ask them who makes the tank, call up the manufacturer and ask them how the tank is made. Then you'll have the real answer you're looking for.

I put a gasser tank into my diesel. Physically the tank fit just fine, however the sender did not. There are locating tabs that align the sender with the tank, they are different for gas vs diesel senders. About a minute with a die grinder and I solved that issue.

As far as evap goes, I think the difference is in the vent/rollover valve at the top of the tank. The one I pulled off my diesel tank had one tube that was a vent. The gasser valve had two tubes, one was a one way vent line to let air in as you use up the gas. The second tube was for vapor recovery and it went up to the canister in the engine bay.

 

I should have put quotes around "galvanized", I was just referring to it in that sense because I wasnt sure of the proper term... Trust me, I work in HVAC, I've had zinc poisoning several times, I understand that galvanizing means zinc plated, however, is it something to make a big deal about....probably not... Im glad you posted the proper term so us dummies know now .

And as far as the senders went, mine dropped right into my gasser tanks, no mods. Senders were from the 88, tanks were from the 89.

 

So.. (I hate it when I do this...) along similar lines anyone know anything about the aerotanks larger tank(s) for our trucks? Costs almost double but there baffled, aluminized, have a drain plug, slightly larger capacity and bolt straight to the frame vs straps. (waiting to here back about fuel sender and skid plate). Also have a matching midship tank you can get for a total of 85 gallon capacity And the only reason why Id want that large a fuel capacity is every year I tow my 24' 8klb car trailer 800miles (one way) from Denver to SLC and its a lot quicker/nicer to not have to stop as often (got spoiled back when I had an open trailer and a 1/2 ton truck that went 500miles on a tank)

All that said Ill still probably talk with my wallet and get the LMC rear tank since Im broke, my random guess on the specs for it is just a regular Bronco tank that they built a hardware kit to bolt onto our trucks (although Ill admit Im not a fan of modifying fuel senders)

For those interested heres the links for the Aerotank brand ones Rear and Midship (this ones weird because the list view for all Fords lists it as a Diesel tank but detailed view lists gas, trying to confirm now)

 

So what exactly happens if the diesel removes the zinc coating? I can't see the tank getting hurt, not sure about the ip or injectors, I think it would just go right threw. Anyone know?