I just had that issue last week when I left for a camping trip. I took a right hand corner and l/r-kitchen slide came 3/4 of way out.
Almost pooped my shorts. Pulled off road and switch pulled slide in slowly. Just had coach in service for slow moving slide-out. They said it worked fine.
Called them and told them I needed help and what to do....took coach to them. They checked the reservoir and it was empty! Filled reservoir and works fine now.
Talked with service writer and head management and he was steamed to say the least.