I am looking at purchasing a CAT V40B forklift. It has a few issues though. I has a sluggish throttle response and supposedly the hydraulic pump is worn and as it heats up it doesn't want to lift heavy loads. The order says he had it looked at and the guy told him it was a gear pump and therefore, not serviceable. I've never heard that but I'm asking instead of assuming.
Could be a few things on sluggish throttle from a basic maintenance issue like filters to a more worry some issue. Could be the pump thats a sign pumps are going south once the fluid this out with head they start to bypass. Usually on those gear pumps its either that case or internals are worn and out of tolerance and thats when rebuilding them is not cost effective. Just depends on what is actually the issue once you break it open. Only way to be 100% certain its the pump would be pull it and have it put on a test bench. But as mentioned that is a usual tell tell sign a pump is having issue.