fuel tank leaks at sending unit and pump

[Frankb]

I put a new TanksInc tank in my Charger a few years ago. This tank has an in-tank electric pump so there are two openings at top of tank. I noticed leaks almost immediately. Leaking at fuel sending unit and fuel pump opening. Sending unit and fuel pump installed per TankInc instructions. I used the seals that came with the tank. Well I finally removed the tank to facilitate other maintenance. I removed sending unit and pump. Both gaskets look perfect and tank mount surface looks perfect. I did not use any RTV or other sealer on initial install. My thoughts are to use some black RTV however, this should not be required for a leak free seal. Has anyone run into this problem with this type of seal? If so how did you fix it. Thanks
Frank

 

[QOTHL]

It sucks at $4.90 a gallon.

 

[493 Mike]

RTV is gas soluble. Look elsewhere for sealants.
Mike

 

[Wietse]

Did you reuse the old gaskets or did you get new ones?
If used before they will not compress "as new" and not seal properly.
You might get away with a light coat of Permatex, that should be fuel resistant.
Best is get new gaskets (OEM) from same material.

 

[440SportSatellite]

I used Indian Head Gasket Shellac on the seals for my tanks, inc. tank. I saw they recommended that somewhere in all the reading up on it I did before the install. I was concerned it would leak, read some reviews complaining about it, but it hasn't in 3 years.

 

[pnora]

Does it leak when running? Does it leak while sitting with no fuel pressure on the lines? First thing I would do is be sure it is from the gasket. Gas is clear and can wick to certain areas making it look like the leak spot where it is not. Are all the holes blind? Make sure they are. Fuel could be wicking up the threads. Lastly call Tanks and ask them for an opinion. They may have had others with this problem and may have a simple fix. They may also have an improved seal. Wont know until you ask.

 

[Frankb]

Copy all on the RTV.
I used new gaskets. The ones that came with the tank. Justin at Tanksinc sent me a link for "premium" gaskets. I will order and try those. He also told me most likely cause for leak was tank vent issues. This tank was vented and as far as I can tell vents were good. One vent went into tank filler tube and the second vent directly to atmosphere.
Unknown if leaking when running. When I would park the car in the garage I had to put a drip pan under the tank to catch the fuel: it was more than a few drops. Fuel was coming from top of tank where fuel pump and sending unit go into tank. When I removed the tank yesterday there was evidence of fuel leak from both theses places

 

[pnora]

I would assemble the tank. Cap the lines. Stand it on end and put enough fuel in it to submerse those areas. Then let is stay like that foe a day or so. Better to be sure now than to have to pull it and do it all over. Did you check all the screw holes? Sealing washers on all the screws to be sure.

 

[Wietse]

Unknown if leaking when running. When I would park the car in the garage I had to put a drip pan under the tank to catch the fuel: it was more than a few drops. Fuel was coming from top of tank where fuel pump and sending unit go into tank

So according this it is leaking while standing still with engine off. (No feed pressure, no fuel sloshing around from accelerating/braking)
You sure it is not any of the fittings that leaks and flood the whole area which makes is look like the pump and sending unit gaskets are leaking.
Fuel line will still be pressurized once shut down so it might leak at that time which makes you find it leaking in the garage.

 

[WileE]

I used Indian Head Gasket Shellac on the seals for my tanks, inc. tank. I saw they recommended that somewhere in all the reading up on it I did before the install. I was concerned it would leak, read some reviews complaining about it, but it hasn't in 3 years.

Smart guy.

 

[matthon]

Is that their in tank npt pump?
Imo it's junk and leaks.

I put their sending unit block off plate with their gasket, neoprene iirc, and bolts with their o-rings at THE BOTTOM of my wagon gas tank to cover a rusted section, small, cut it out, and it doesn't leak and hasn't for years.

My point is, I doubt it's their gasket.

 

[Frankb]

The possibility exists but its remote that the fittings are leaking. When everything was together and I first noticed a leak I went under the car and did a visual. The lines are well above the gaskets and I could see them clearly. I saw no fuel on the fittings. I believe the fuel is coming from the gasket surfaces. Additionally it only leaks when the tank is full or mostly full. Drive the car for a little and get some fuel out and the leaks go away. I drove it like this for a year or so.
Unfortunately with this setup you must use NPT to pump outlet. I had to use a long NPT to AN fitting (4 inch IIRC) for clearance issues. However the lines are all supported and minimal weight is on the fitting itself.
Once I get the new gaskets I will do as pnora suggested and do a leak check on the gaskets prior to install. And yes there are O rings on each screw used to secure the pump and sending unit
Frank