Bladder Tank Issue

Hi

I have run into a little problem with my Cessna 182. It is fitted with long range bladder tanks which are now behaving rather odly.

Someone recently hired it to fly long distance. When the plane arrived back, the right-hand tank appeared to have been flown dry, and the bladder was sucked upwards towards the filler cap. The lefthand tank still had a reasonable amount of fuel in it.

We refilled both tanks and the bladder base went back down, it did however appear to have formed a crease right at the point where you dip it to check the contents. Additionally we also discovered that the filler cap on the righthand tank does not seal properly. This was simple to rectify by tightening the cap assembly.

Since then, the righthand tank capacity has shrunk by about 40 liters. My local engineering company assures me the bladder could not have folded in on itself because it is held securely by some clips. I am stumped where the capacity has gone!

The only logical explanation I can come up with is that the crease at the dipping point is positioned just right to hide 40 liters.

Does anyone have any suggestions?

Thanks

Francois