Water leak on slide

[exfed12825]

I have a 2008 Coachmen 40 ft toy hauler with 2 slides. The living area slide is leaking around the top seal in the rear. I tried adjusting the leveling screw but still have a 1/2 inch gap in the top corner and have run that screw all the way out. I tried sliding the 2 bolts on the slide arm to move the slide out farther but still have that 1/2 inch of daylight in the top corner. Any sugestions on how to fix this before the floor rots out.