Fixing a Grumman Fuel Tank Leak
or
How I Spent My Summer Vacation

Before

This first set of pictures shows the initial reconnaissance of the problem area.

The fuel tank was drained by removing the sump tank drain. Fortunately I didn't have a whole lot of fuel in the tank, and what was there was bucket-ed over to the right wing tank.

The four fuel tank covers were removed. I considered just removing the two outboard covers, since that's where we would be working, but decided to remove all four to facilitate access with droplights and vacuum cleaners. One cover was starting to show signs of seepage, so I was probably going to have to reseal all of them anyway. Removal was accomplished by removing all the screws and gently prying off the cover. Where access to the inside of the cover was available (all except first aft cover to come off), the cover was loosened by sliding a putty knife between the cover and the mounting flange inside the tank.

Top/forward area of tank looking up through the outboard/forward access hole. Visible are the filler cap opening, the vent line, and the quantity tab.
Close-up of that same area.
This shows the area outside the tank, showing the top of the spar and the outboard tank rib. No leakage is visible in this area.
Underside of the wing with the seam strip removed. Forward is to the right. and the fuel tank is towards the top of the picture. Leakage is evident on the back side of the spar, visible through the opening.
Backside of the spar outboard of the fuel tank. The outboard rib of the fuel tank is on the right. Again, leakage is evident on the back side of the spar. The crazy angle is not an attempt to create dramatic effect, but is the result of trying to get the camera through a hole that's smaller than the camera.
Another view of the outboard rib aft of the spar.
This shows the area in the fuel tank aft and below the spar.
Fuel tank aft and above the spar.
Fuel tank forward and below the spar. The quantity tab is visible in the upper portion of this picture.
Close-up of a suspect area. We speculated that perhaps this area wasn't sealed well at the factory. Then again, it really didn't matter. We were going to reseal the whole area around the spar anyway.