If the leak is truly ate front AND the back of the slide, maybe this is normal in heavy rain. RVs are not hermetically sealed units. Could you install wheel splash guards? Check the entire seal length for levelness. Make sure, if you have the new track system that you re-synchronize it and follow the instructions, leaving the switch on for a couple of seconds (they suggest 5 seconds) after the slide is fully extended and when retracting it as well. There are two separate motors driving these tracks and they are not perfectly matched, so leaving the switch on after closing and opening makes sure both motors have reached their stalled, higher current limits that only happens when both motors have pulled the slide in or out all of the way to their "stops".
__________________
|