You need to locate the breaker that protects the hydraulic pump. That hydraulic pump does the work for both the leveling system and the slides.
Follow the heavy red wire from the solenoid, located on or near the pump, to its breaker
You can do an 80 amp upgrade, but most, including myself, have found that just replacing the 50 amp breaker with another 50 amp will do the trick.
A 50 amp breaker will be under $10.
Peace
Dave