85 GMC Sierra Classic 1 Ton Crew Cab

[Mattman2010]

Ok I guess I understood my dad wrong, he said turn the tank over and trap the air in the tank and push it under water. I guess we will probably try that and if it doesnt work then I will weld the top on.

[ryanroo]

that is better, but youll want some soapy water to spray the seams with. i doubt youll be able to totally submerge that tank. that is a lot of buoyancy.

ryan

[Dieselwrencher]

Originally Posted by ryanroo

that is better, but youll want some soapy water to spray the seams with. i doubt youll be able to totally submerge that tank. that is a lot of buoyancy.

ryan

Something tells me with Matty, there will be a tractor and loader involved at the least.

When I check tanks and stuff, I use a pressure regulater and soapy water like Ryan mentioned. I also learned the hard way on water while testing an oil pan I modified................

[Mattman2010]

Originally Posted by ryanroo

that is better, but youll want some soapy water to spray the seams with. i doubt youll be able to totally submerge that tank. that is a lot of buoyancy.

ryan

That is the plan!

Originally Posted by Dieselwrencher

Something tells me with Matty, there will be a tractor and loader involved at the least.

When I check tanks and stuff, I use a pressure regulater and soapy water like Ryan mentioned. I also learned the hard way on water while testing an oil pan I modified................

hmmmm.... now you have me thinking. I dont have a tank big enough to test this tank in unless I go up to my uncles and use his cow waterer, but that tank is nasty. I have a couple tarps laying around and the bed of my truck.... And yes I have a tractor so I could use that....

[buckshot305]

Before underground storage tanks for gas stations are set and buried, they are pressurized and a pressure gauge is installed. Simply let it sit overnight and see if the pressure dropped. No change means no leaks. If it's good enough for fuel in the ground, should be good enough for a truck. I would use a decent 0-10psi or similar gauge and pressurize to 10psi. Spray seams with soapy water.

Also, Ultra Low Sulfur Diesel fuel is very nasty on steel, causes it to rust pretty bad over time. Don't know why, but I would think about a spray on coating designed for fuel tanks. I'm sure there's something out there for this application.

Awesome build thread too!

[Mattman2010]

40 gallon of air at 10 psi would probably blow this damn tank up. I plan on getting a coating kit for the inside.

Thanks man!
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[Mattman2010]

I did get the tank all welded up yesterday, but stopped there cause I think this changing weather is starting to make me sick.



Waiting on a bunch of parts to come in for the tank. Pretty sure I have everything figured out but going to wait to put the fittings in the tank after it is installed so that I can make sure I have clearance for everything. I have also decided to put the filler in the bed. I dont haul to much stuff and we bought a 16 foot trailer a couple months ago so i should be good to go with that. Plus me and sheet metal are not friends so there is no way I could move a fuel door to the back and make it look good.

[1985-GMC]

You could move the door, just tack tack... tack it in.
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[maxxxy]

Originally Posted by 1985-GMC

You could move the door, just tack tack... tack it in.
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Hahaha This comes to mind.

Happy Gilmore - Just Tap it in... - YouTube

[Mattman2010]

Yeah the one time I did some body work cutting out pannels I messed it up bad. People may not like the filler in my bed but doest really matter to me. Works for me!
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[ryanroo]

looks alright to me!

[1985-GMC]

LOL that's what I was going for, glad someone got it!

[Dieselwrencher]

Nice work Matt. You can weld in the fuel door, just go slow. Heck, why not just get one of those billet ricer type gas doors? It'll match your no sleeve shirts and flat billed hats..........

[Mattman2010]

Originally Posted by 1985-GMC

LOL that's what I was going for, glad someone got it!

You would...

Originally Posted by Dieselwrencher

Nice work Matt. You can weld in the fuel door, just go slow. Heck, why not just get one of those billet ricer type gas doors? It'll match your no sleeve shirts and flat billed hats..........

The main reason I dont want to weld in a fuel door is this will not be the bed that I am going to be keeping. This bed is just a bed that I can use to get the truck running, I plan on running it as a dually so I will need to get a dually bed at some point and would hate to do all this work on a bed I dont plan on keeping. So the billet fuel door is tempting.

[Mattman2010]

Got some parts in.



Got the sending unit, 3/4" pipe thread plug with weld in fitting for a drain in the bottom of the tank, also got some 1/2" T-bolts for the fuel tank straps (Yeah probably over kill, but this thing is called "The Tank" haha), also got a vent for the tank, but thinking about using a different setup already because with this vent just mounted on the tank I could easily overfill the tank and this vent wouldnt work. Thinking about putting an AN fitting in the tank and get some hose and mount a filter up higher on the bed or something like that because Dieselwrencher gave me a couple more different ideas for filling the tank that I plan on looking at today.

[Dieselwrencher]

You should just get an antirollover vent from a place like speedway motors. That way if the DOT ever checks, it will be legal.

[Mattman2010]

Yeah I will look into those.

Test fitted the tank. Gotta cut the rear cross member out and weld it in and then get some angle iron for the front of the tank for its mount. Not sure what to run as a buffer between the tank and the cross member mounts.

[maxxxy]

On my gas tank I had an 1/8" thick old tractor tire inner tube that I cut into strips and used those to cushion it from squeaking.

[Mattman2010]

Originally Posted by maxxxy

On my gas tank I had an 1/8" thick old tractor tire inner tube that I cut into strips and used those to cushion it from squeaking.

Yeah I have been thinking about using an old inner tube for the cushions as well I have a couple laying around.

[Mattman2010]

Today I started messing around with the cross members for the tank. Need to get it basically mounted so I can figure out where to best put all the fittings for my tank.

Rear cross member


Front cross member


over view of how the tank sets in the frame


Kinda what my mount situation will look like


You can see the steel plate i have at the back of the tank, that will be cut in half and welded to the top of the rear cross member. It will be where the tank pushes up on when the straps are tightened down. The front cross member is a piece of angle iron so the tank will push up against that.

I am also looking at ways to fill the tank. Right now I am looking at using the stock filler and mount it in under the drivers side bed rail kinda like so.


I then plan on making a box that looks like this for housing the stock filler.

[Mattman2010]

Messed around with the tank some more today. got the front cross member tacked in and then started working on the tank straps.



Front mounts started for straps.


Rear mounts have yet to be finished.

[ryanroo]

looks like a roll over vent in the picture?

[Dieselwrencher]

Originally Posted by ryanroo

looks like a roll over vent in the picture?

Matt, shake it. Does it rattle?

[Mattman2010]

Originally Posted by ryanroo

looks like a roll over vent in the picture?

It is. There is a filter on the top of it but there is no way to put a hose on it. With the way that I am planning on putting my filler I could easily over fill it and have fuel running out of it. Thinking about using the stock filler up under the drivers side bed rail, seems to be plenty of room for it there.

Originally Posted by Dieselwrencher

Matt, shake it. Does it rattle?

It does!

[ryanroo]

fancy drawin' program you got there!

the straps are looking good. are you going to weld that wrapper back to the flat bar where it wraps the T-bolts?