Need help with a fuel tank leak.

[AX-O]

Well, I guess half of my prayers were answered. One tank out of two is leaking I let the proseal on my tanks cure for about 2 weeks prior to pressure testing them. I pressurized the tanks for about 24 hrs. One of the tanks was good to go (99.99% sure). The other one, not so much. The water level dropped about 2.5 inches over 24 hours. After applying soapy water to every inch of the tank I found a very small leak The leak is coming from the BNC connector. Not from the outside of the connector but from the inside. To be more specific the leak is coming from the small hole in the middle of the connector. I did the same thing on both tanks and applied proseal to the wire and the BNC connector after crimping and soldering the wire. Should I take the access plate off and apply more proseal to the connector prior to resealing the tank or should I replace the BNC connector all together and reinstall the assembly?

[bullojm1]

Axel-

Sorry to hear about your leak! At least it is easily fixable! Could be much more buried in these tanks. I don't think you need to replace the BNC connector, just be sure to cover it liberally. Here is a pic of mine:

http://www.rvplane.com/showthumb.php...e=IMG_6694.JPG

Good Luck!

[brenegan]

wick in some green loctite

[vmirv8bldr]

Same thing happened to me, I thought it was really wierd. I mixed up some Proseal and globbed it on the back of the connector, then smeared it all around it. Let it cure for about a day then tested again...no leak.

[N941WR]

Originally Posted by vmirv8bldr

Same thing happened to me, I thought it was really wierd. I mixed up some Proseal and globbed it on the back of the connector, then smeared it all around it. Let it cure for about a day then tested again...no leak.

Ditto for me. This is a common leak area. You really need to cover that thing up with a LOT of pro seal.

[AX-O]

Well guys, it did not work I pulled the access plate off and applied A LOT of proseal to the back of the BNC connector. I found a spot that looked suspect and covered it up along with the rest of the connector and wire. Then I let the proseal cure for 10 days prior to testing it. The leak is still there and is leaking at the same rate (kind of like I did nothing to it).

Is it possible for the electrical wire to have a hole on the outer cover and the air is entering it and escaping trough the BNC connector? Seems stupid however, I've covered the BNC connector very well twice now and no joy. I did the same thing to the other tank and it did not leak

Any more ideas???? I want to put these tanks behind me.

[Mike S]

Originally Posted by AX-O

and applied proseal to the wire and the BNC connector after crimping and soldering the wire.

Wires have two ends.

What did you do to the other end??

[ten4teg]

What is a good way to pressure test the fuel tanks?? I saw on this post that you pressurized them and the water level dropped. How does that work. Did you fill the tanks with water and then pressure test it? Also, what are good connectors to do a pressure test with? Thanks, Tom

[AX-O]

Originally Posted by ten4teg

What is a good way to pressure test the fuel tanks?? I saw on this post that you pressurized them and the water level dropped. How does that work. Did you fill the tanks with water and then pressure test it? Also, what are good connectors to do a pressure test with? Thanks, Tom

I used the kit from Vans plus a few other AN fitting caps. The kit provides a valve (kind of like on a bicycle tube) that screws onto the fuel drain attach point. You use that to pump air into the tank. The part number from Vans is indicated below.

Fuel Tank Test Kit
Part Number = FUEL TANK TEST KIT
Price = $5.00

Two ways to do it:
1. Place a balloon on the fuel vent AN fitting. Inflate the balloon by pressurizing the tank. If the pressure inside the tank is above approximately 1 PSI, the balloon should pop and prevent damage to your tank.

2. The other way is by using a manometer. Connect a clear hose to the fuel vent AN fitting, fill the hose with water, then pressurize the tank so the water level on the open side of the tube is approximately 2 feet and 3 inches higher than the side attached to the tank. That will ensure approx 1 PSI inside the tank. You will see variation on the water level due to Pressure and Temperature. The ideal gas law (pV=nRT) explains the relationship. Pressure is directly related to Temperature. Temp goes down and so does Pressure.

Hope that helps. If you need to see pictures and what I did, check my log page. http://www.mykitlog.com/users/displa...og=47689&row=3

[AX-O]

Originally Posted by Mike S

Wires have two ends.

What did you do to the other end??

The other side of the wire is attached to the fuel sender plates. The wire was soldered and crimped to a connector. Proseal was then applied to the wire, the connector, the bolt and fuel sender plate.