gas tank replacement -- any tips before digging in? (1 Viewer)

[dkcrew]

The tank is rusting from the inside out ... so I'm finally getting around to replacing it. I have a new tank, along with a new sending unit and new hoses if I need them. The process looks fairly straightforward, but If anyone has any "I wish I would have known" tips they'll be appreciated.
Thanks -- Dave

 

[B y r o n]

I didn't care for the felt like pads used to cushion the tank from the floor as they would seem to hold moisture and cause rust. Take a look at post #42 in this thread for my solution.

 

[peesalot]

careful with the pick up fitting if you still have the oem one, dont bugger it up. did the new tank come with one ??

 

[dkcrew]

didn't take long to find problem #1. The plastic into the fuel separator was cracked and just sort of wedged in place. going to track down one of these and replace the hoses while in here.

 

[Mr. Green]

Only tip I would have is the rule of Pi when working on this. In that it will take you three times as long as you planned!

 

[sggoat]

if you got a CCOT tank--clean it good inside(maybe even tank sealer?). then POR15 the whole outside-esp the bottom

 

[cruisermatt]

be sure to have this on hand as the originals are usually crack upon disassembly

40 Series Fuel Tank Hose #1 — CruiserMatt's Off-Road & Performance

Fits all 3/69- 6/80 FJ40/43/45 & Diesels Also fits a variety of Hilux/Tercel/Corolla Replacement for the previously discontinued fuel tank hose OEM#: 90445-22907 Also replaces the superseded discontinued fuel tank hose OEM#: 90445-22009 Includes 2 clamps

www.cruisermatts.com

 

[dkcrew]

if you got a CCOT tank--clean it good inside(maybe even tank sealer?). then POR15 the whole outside-esp the bottom

I talked to CCOT and they said I shouldn't have to do anything to the inside of the tank. What would you recommend as the best way to clean the inside of the new tank?

 

[rainingagain]

Any new tank, it's probably a good idea to at least blow it out with air. Who knows what dust or small crap could have gotten in there.

I am in early tank replacement hell right now but from the pics, your's looks like the later model that's still available from Mr T. Seems you got one from from CCOT. Those from my research have a good rep.

As far as coating the inside of a new tank, I would do it. Modern tanks are plastic for safety and because modern gas is corrosive. If you are going to run modern gas that will sit for really any period of time, you'd be surprised how much water vapor it attracts. Your new metal tank will be rusty before you know it. I'm going to POR15 mine. But I'll be sure to follow the manufacturers instructions EXACTLY. Especially the prep. I had a buddy that claimed to follow the prep instructions but within a few weeks he was pulling huge chunks of the coating what was just flaking off. It was a mess.

 

[rainingagain]

Is your new tank galvanized?

 

[dkcrew]

Is your new tank galvanized?

yes it is galvanized. and yes it is from CCOT. My old tank is a '73 (original).

from their site >> "CCOT's new tank is exactly like the original in every feature, measurement, fitting and metal thickness. Replica tank is made with galvanized steel to prevent rust and Primer Coated. Replica and OEM tanks hold 16.4 US gallons of gas. Poly tank holds 12.5 US gallons of gas.

All tanks are pressure tested twice by Maker for leaks prior to shipping. Tanks are shipped in heavy triple ply cardboard boxes protected with heavy cardboard inserts.

We believe this FJ40 galvanized steel tank to be the highest quality available."

The tank does look good and I've confirmed fitment. I will be blowing out air but I am not planning on doing anything on the inside so we will see if I report back in some time. My existing tank is definitely rusting from the inside out ... and outside in ... so I'm looking forward to this.

I started the process Sunday but realized I need another fuel line and need to fix that fuel separator so it will likely sit for 2 weeks until I can find a bit more time.

 

[Blue77FJ40]

If you use POR15 gas tank coating, read directions and use the amount recommended. You only get one shot at it, because you can’t add more later to cover a missed spot. It will not stick to itself. BTDT.

Also, you should mark the hose ends and their fittings to ease where what hose goes where for installation.

Plan to replace all soft lines. I’d suggest marine quality hose. I found a number of rotted sections on mine.

 

[ducktapeguy]

didn't take long to find problem #1. The plastic into the fuel separator was cracked and just sort of wedged in place. going to track down one of these and replace the hoses while in here.

View attachment 3264171

View attachment 3264172

I wouldn't bother trying to track down a used one, any one that you find is still going to be 40+ years old and will just crack again. Just get an aluminum air manifold and some hose fittings and make a new one that will last the rest of your life.

 

[dkcrew]

I wouldn't bother trying to track down a used one, any one that you find is still going to be 40+ years old and will just crack again. Just get an aluminum air manifold and some hose fittings and make a new one that will last the rest of your life.

View attachment 3268407

great idea - thanks. I've had to set this aside and will knock it out 2 weekends from now so I may get this part ready in the meantime. In layman terms are the fuel vapors flowing from the tank through this to the charcoal canister with the check valve in between?
- tank > fuel vapors > separator > check valve > charcoal canister?
thanks!

 

[dazerb]

great idea - thanks. I've had to set this aside and will knock it out 2 weekends from now so I may get this part ready in the meantime. In layman terms are the fuel vapors flowing from the tank through this to the charcoal canister with the check valve in between?
- tank > fuel vapors > separator > check valve > charcoal canister?
thanks!

Following... this is my next project. Rust pinholes fuel leaking and rust powder gumming up my filter and carb bowl. 1974

 

[igotta40]

I bought a OEM tank. It had a very thin coat of paint on the bare steel (no primer) so I primed it with Rustoleum primer and brush painted it with oil based enamel. Same for the cab floor. Ditto on replacing the fabric cushioning with rubber. I also replaced the fill & vent hoses.

 

[brooklyn]

I would suggest adding a second fuel filter - at least for the first few tanks of gas. You don’t want to pick up any debris and clog the carburetor.

In my two tank system, I have one fuel filter before the switching valve and one after — maybe not necessary, but a fouled carb is not a fun repair project.

 

[dkcrew]

I would suggest adding a second fuel filter - at least for the first few tanks of gas. You don’t want to pick up any debris and clog the carburetor.

In my two tank system, I have one fuel filter before the switching valve and one after — maybe not necessary, but a fouled carb is not a fun repair project.

Too late for the fouled carb but I like the idea. I’m away from the truck for the next 2 weeks but I now have all the parts and hoses for reassembly when I’m back.

 

[69FJ40NJ]

Does someone make a stainless steel tank?

 

[dkcrew]

The tank replacement was pretty painless. I did sand > prime > paint the body underneath to protect it a bit better going forward so it took time in terms of hours. And used some 1/8" rubber strips between the tank and the floorboard. Replaced some hoses and re-used others. The gas cap fits much more snug on the new filler cap (not sure why) and I was able to drive about 20 miles yesterday. The thing I noticed the most was the lack of gas smell. I figured fumes were coming out either from pinhole leaks or hoses and connections somewhere in this process ... that problem has been solved. And it's just as nice to see clear fuel flowing through the filter. Success! Carb adjustments and a possible rebuild next up once I get more miles and confirm clean gas.