Remove the bladder from the aircraft in order to test it. Allow the bladder to dry thoroughly, then perform an intensive visual inspection to check for leaks, cracks or holes.
Perform a pressure test by taking a white cotton sheet that has been soaked in ammonia phenylthyline and wrapping it around the bladder. Then pour pure alcohol into the bladder. If there is a leak in the bladder, a red spot in the area of the leak will appear on the red sheet.
Take note of the locations of red stains on the white sheet.
Use a hand dispensing gun to seal any cracks, holes or leaks with a specialty rubber sealant designed for aircraft cells or bladders. The type of sealant used depends on the type and weight of your aircraft's bladder.
Allow the sealant to dry and then retest for leaks. If no red stains appear on the second test, reinstall the bladder. If red stains appear, repeat the sealant process until the bladder is leak free.
