can gas leak where water can't? Fuel Sending Unit

[aaronmichorn]

Having trouble sealing up a new rear gas tank. Third try and the tank still leaks. New plastic tank, new sending unit, new seal, new lock ring. I drained the gas out of the sending unit hole today down just below the level of the hole. I jacked up the backend to get a little more out of it. The fuel level was about 1/2" below the hole. I dried it off, and started reinstalling with RTV when I notice fuel was still slowly leaking out. I pulled everything back out and dried it off again, and lit a match to see what I was doing ( actually a flashlight). there was fuel coming out of one of those gimpy retaining clip bolt holes. I thought maybe there was a crack inside of the tank backing up to the threads for the bolts.

So, I drained the entire tank, and removed it from my truck. I filled it with water up to the lip of the hole, and no water was leaking at the bolt hole anymore. Any ideas?

 

[wildbill]

;D ;D ;D Yes gas and oil will leak were water wont and watch your RTV as a lot of it WONT work on gas good luck. Bill ;D

 

[aaronmichorn]

I bought this gas tank about 9 months ago, but just within the last couple of weeks have fired up the bronco, and got around to filling up the tank for the first time. That is when I discovered the leak. Is there something I am not doing right trying to seal up the sending unit, or is it possible that it really is leaking out one of the bolt holes? I guess anything is possible.

 

[prtylikarockstr]

same problem

my tank is doing the same damn thing its a factory one though. i have pulled it out 3 times and am startin to live with it but at $3 a gallon its getting harder.

 

[a74ranger]

I also had a similar problem - trashed the tank and bought a 24 gal steel tank from BC Broncos