Kubota u55 - 4 loss of power

[nautickleone]

Looking for advice to understand why my 2nd hand excavator looses power when hot.
Just bought it privately with apparently 1020hrs and previous owner denies any problems. Abit sluggish when cold and now changed all filters and replaced oils. Initially seemed better but as soon as it's hot looses alot of the hydraulic power particularly to track drives.
Any thoughts welcome please

 

[Melensdad]

I’d be looking at the hydraulic pump and also the hydraulic fluid level

 

[Kevlar]

Only way to know for sure is to check pump pressure. Could be a relief valve acting up or the control valves leaking internally. Have you used other hoes of this size to compare it to? They aren’t real big machines so some people get in one after running bigger machines and expect them to do things they aren’t capable of. Is it just losing hydraulic power or possibly engine power?

 

[Kevlar]

I was just doing some reading on that machine, sounds like you can adjust the hydraulic flow for each function, something to look into. Also sounds like it has an economy mode and can be pretty weak if in that setting.

 

[m1west]

Is the engine losing power when it heats up, or is the engine fine and the hydraulics losing power?
If it’s a hydraulic issue, start with the suggestions already posted
If the engine is losing power when it heats up, start with checking valve lash as equipment usually has mechanical lifters.
If that’s not it, move to the fuel system.