driver's side fuel tank leaking - 99 FLD

Pretty common.
This issue can be extenuated
by years of truck washes using acid to brighten the tanks.
I have seen tanks reduced to paper thin because of to much acid washing at truck washes...

 

They wear out on a kw too.....
When I had my truck painted I had the tanks bottoms welded and put new rubbers......and I split a tank just for fun.

 

Salt and sand get between straps and tanks and eventually sand a hole through them. Years back when sand was more common you’d see trucks 4 years old leaking already. Best preventive maintenance is washing more after bad weather.

 

One day this summer while home I noticed something hanging under my 2013 cascadia so i headed straight to the shop .
It was a broken tank strap , further inspection revealed all 4 straps were corroded to the point that a ball point pen could be pushed thru the centers .
My tanks are behind the fairings which doesent help the corrosion issue .

 

When repairing tanks I put air on them to check for leaks with window cleaner. It does not take much pressure if it has air at the spot leaking. With my shop regulator I know to stop as soon as I hear air going through it. May not even read on the gauge. Someone holding a leaf blower in the neck with rags to seal it would probably even work.
If it is just a pin hole skuff it up up real good with rough sand paper. Put a piece of 2 inch masking tape about a 1/2 inch below the leak. Only the bottom of the tape is attached. Then mix and apply JB weld to the leak area above the tape. Fold the tape over to seal the ends and top. That holds the product in place. Good to go tomorrow.

 

Over a 22 year period that is a lot of time for things like vibration, chemicals and other natural elements to do their work on the tank so yes is will corrode and wear out a tiny hole/ crack in the tank.

 

Great idea all RC needs to do is apply air through the vent hose the check valve should keep pressure in tank . That’s the way I’ve primed reefers that were out of fuel when I picked them up. Apply air pump on filter then it fired up . Just loosen cap after to release excess air after.

 

Once you find the hole I've had excellent luck with two different epoxies. PC Metal and Marine-Tex. I had a stainless tank trim/ fairing eat a whole in my Pete's tank a year after I got it. I fix it with PC Metal and it's still there 6 years later. I have an 88 Kenworth with a patch of Marine-Tex on it from 1996.