Fuel problems persist

[Booyah45828]

If your sending unit is that bad, I'd be looking for replacements.

If you have a few weeks where you don't have to move, you could try draining and then filling the tank with a molasses and water mixture. Doing that will convert the rust in the tank and you can dump it down any drain. Then clean the tank spotless and fill it back full of diesel.

[Native]

What sort of ratio between molasses and water? 50/50?

[Booyah45828]

I used 7 parts water:1 part molasses when I did it in a garbage can. I read elsewhere that you can try anywhere from 5-10:1 as a ratio and it will likely work. If I was in a situation where I had more time then money, I'd give that a try before I replaced the tank.

[Mat7783]

My lovely tank. Draining it tomorrow to see how bad is it?

[EastCoastCB]

Good job, man!

[Native]

I do not want to think about removing our tank. There is a huge cage around it and I have no idea how it is attached.

[banman]

Originally Posted by Native

I do not want to think about removing our tank. There is a huge cage around it and I have no idea how it is attached.

Now I'm curious -- mines centered between the frame rails and bolted to the frame rails like a x-member. Yours being outside the frame rail has to be different -- but if it's tied to the frame rail and the sub-floor, wouldn't that interfere with the body sliding on the frame in an accident?

[Booyah45828]

I'd be surprised if it is.

It's likely attached via straps that are bolted on to some L brackets that are bolted or riveted to the frame. That's how most saddle tanks are mounted. A mid mount would be different, but it still shouldn't be attached to the floor in any way.

The tanks would be installed by the chassis builder, so both of your buses being freightliners, they'd be attached to the frame by freightliner before thomas even had a chance to mount the body.

[banman]

Originally Posted by Booyah45828

I'd be surprised if it is.

It's likely attached via straps that are bolted on to some L brackets that are bolted or riveted to the frame. That's how most saddle tanks are mounted. A mid mount would be different, but it still shouldn't be attached to the floor in any way.

The tanks would be installed by the chassis builder, so both of your buses being freightliners, they'd be attached to the frame by freightliner before thomas even had a chance to mount the body.

Hard to imagine all that weight cantilevered off the outside of the frame rail...
Native's 65 gal tank + crash cage.

Like I said, I'm curious...

[Booyah45828]

It is though.

Semi trucks can have 150 gallon tanks cantilevered off the side of the frame rail with 3 or more of those L brackets and straps holding them on. That's 1000+ lbs of fuel alone hanging sideways off a frame rail.

If they have dual tanks, they can put a panel/braces between the tanks towards the bottom to give it some rigidity, but I've never seen any with brackets that hold it from the top or off the cab.

[Native]

Originally Posted by Booyah45828

It is though.

Semi trucks can have 150 gallon tanks cantilevered off the side of the frame rail with 3 or more of those L brackets and straps holding them on. That's 1000+ lbs of fuel alone hanging sideways off a frame rail.

If they have dual tanks, they can put a panel/braces between the tanks towards the bottom to give it some rigidity, but I've never seen any with brackets that hold it from the top or off the cab.

You got me real curious so I rummaged through a few pictures I have and viola ...





That is the rear mount. I am assuming there is at least one like it in front as well and maybe one in the middle. Perhaps I'll take a look when I go out to The Beast later.

[banman]

Originally Posted by Native

You got me real curious so I rummaged through a few pictures I have and viola ...


Attachment 45882


That is the rear mount. I am assuming there is at least one like it in front as well and maybe one in the middle. Perhaps I'll take a look when I go out to The Beast later.

Yup, that's more like what I was guessing -- those are ¼" thick steel brackets (or more!) holding the end of the cage -- I think I measured our frames at only 5/16" thick. So the fuel cell cage is an extension of the frame itself nice..

[Mat7783]

We emptied the tank and my guy said the tank can be salvaged. So I was thinking of pressure washing inside, using Evaporust, then using the POR 15 kit which has a degreaser, metal prep, and tank sealer. Dies this sound like a winner? Any input is welcomed!

[Booyah45828]

Yeah and no. I like the cleaning the tank part. Get as much loose rust and crap out first. And I like the por-15 tank sealer part, because that keeps the problem from happening.

What I don't like is the evaporust, and it's not that I don't like evaporust, it's that a 5 gallon pale of evaporust costs 80 bucks.

You'll likely need more then 5 gallons of it to get the job done.

I'd do what I mentioned earlier and use the molasses and water mix. Fill the tank full of it, install the sender, let it sit for a week or two, dump it, rinse and dry the tank, apply por15, and you're good to go.

You can make 50 gallons of the molasses/water mix for half of what 5 gallons of evaporust would cost. The only real problem is waiting the 2 weeks. I've heard of people using wood bleach in water to dissolve rust that way, but any time you use an acid like that it dissolves other metals.

You need to clean off the sender too, so maybe that might be a project for the evaporust.

[EastCoastCB]

I'd price all the materials and consider the effort/labor, then price some used tanks and see what works out the best.
Could be possible to upgrade to a larger tank.

[banman]

Originally Posted by Mat7783

We emptied the tank and my guy said the tank can be salvaged. So I was thinking of pressure washing inside, using Evaporust, then using the POR 15 kit which has a degreaser, metal prep, and tank sealer. Dies this sound like a winner? Any input is welcomed!

Originally Posted by EastCoastCB

I'd price all the materials and consider the effort/labor, then price some used tanks and see what works out the best.
Could be possible to upgrade to a larger tank.

Yup, that's a lot of chemistry, cost, and hassle...
For the cost of a sending unit -- if the electrical area (the rheostat) got even the slightest bit corroded replace it now -- or you will later...
If the tank cleans up well, then just go with it. Diesel is an oily fuel -- the tank ain't gonna rust with a full tank of fuel in it. Use a fuel treatment. If you ever find water in your fuel/water separator then after the bus has been sitting 24hrs drain some fuel from the bottom of the tank to remove any standing water.

If the tank is pitted, then you know you want to be (at your leisure for a good deal!) shopping for a new tank. As a start look at LKQ online for the price of a tank just to get an idea. There's a thread here somewhere about bus junkyards. A tank from one of them is probably a lot less.

Again, AFTER the tank is power-washed you'll be able to see what the metal actually looks like.
I had a tank I thought was toast and after hot-engine-degreaser-powerwash it turned out every bit of what I though was rusty flaky death was ALL fuel varnish -- I had to replace the pickup sock and sending unit...

I am forever paranoid that any tank coating used will delaminate and become the source of a new problem -- clogging with paint flecks...

[jazty]

I'd also like to add that while I like the Por15 products, they are very picky about prep. I wouldn't deviate much from what they recommend as prep products.

[Mat7783]

I am definitely replacing sending unit as the price is not a wallet breaker. Pressure washing tank tonight to see what I have. I like the molasses treatment but 2 weeks minimum is precious time lost on my build since I have the bus jacked up in wheeley action. Has anyone tried the OSPHO method for the rust issue?thanks for everyone’s input����

[banman]

Ospho is effective -- after you've got the tank cleaned.

I'd put a gallon in and roll the tank a bit to distribute -- I'm assuming there are baffles in the tank to prevent sloshing of the fuel.

After you think you've got the ospho distributed, dump it out. (I'd save what comes out to use on the bus floor or chassis rails or...)

And let it sit. After 24hrs peak into the tank -- it should be dry. You may see a crusty white residue.

I'd probably take a couple of the gallons of fuel you previously drained now and rinse the tank with that and call it done.

I suspect it will be damn near impossible to properly prep the vertical sides of the interior baffles. W/out perfect prep you will likely have product failure with anything you try to coat the tank with...

The ospho will work because it does it's thing on contact -- it's not a coating that will come off but a chemical reaction of iron-oxide to iron phosphate. Your rust will be worst on the bottom and maybe only on the bottom, and maybe not that bad -- like I said -- fuel varnish is the same color as rust...

[Native]

Originally Posted by Mat7783

I am definitely replacing sending unit as the price is not a wallet breaker. Pressure washing tank tonight to see what I have. I like the molasses treatment but 2 weeks minimum is precious time lost on my build since I have the bus jacked up in wheeley action. Has anyone tried the OSPHO method for the rust issue?thanks for everyone’s input����

You could always lower the bus down for the two to three weeks it will take to work on the tank.