What was found
UPON LEVELING OFF AT 4000 FT, THE LT BLEED AIR LEAK LIGHT CAME ON, FOLLOWED QRH WHEN THE LT BLEED VALVE WAS CLOSED, THE BLEED AIR LEAK LIGHT EXTINGUISHED. WHEN THE LT BLEED VALVE WAS TURNED ON THE LIGHT CAME BACK. MAINTENANCE FOUND LT PERRY SEALS BAD & REPLACED LT IB WING SEALS. RAN AIRCRAFT 30 MINUTES, OPS CHECK GOOD.