[fla-gypsy]

Festus is giving you sound advice. All slides are prone to leak at times and some adjustment is necessary. Assuming it was leaking from the top down and if the wiper seal was fully extended as you stated I would examine the area carefully above the slide exterior to ensure all seams and joints are properly sealed. Even the smallest gaps can allow water intrusion during heavy rain. Once that is addressed you may want to adjust the outboard side of the slide down slightly (it has adjusting jack screws) to create a tighter seal at the top. You will also want to make sure that debris has not collected on top of the slide and been drug in where the inner seal makes contact with the interior of the wall. If it is leaking from some where other than the top please indicate that for more information.