Low/slow hydraulic power, what is the cause? Pump possibly??

[kilohertz]

I have a Kubota KX-91 size machine that has slowly been loosing it's hydraulic power, just seems not to have the digging power it used to, it also travels slower than it did 400 hours ago. The engine runs awesome and doesn't slow down at all under load. I have checked/cleaned the hydraulic suction filters, fluid level is correct...I am wondering if it could be the hydraulic pump itself which hangs off the end of the engine, possibly wearing? Are they rebuild able? 5600 hours on it, 500 of them by me in the last 5 years. I have the ability to check line pressures if need be? It's all functions so not just one relief valve.

Any help would be greatly appreciated.

Cheers

 

[Kobelco ireland]

Firstly check the pressures. There is one main relief that if it was failing would cause all functions to be under powered.

 

[kilohertz]

fluid level is correct...

Well, no it wasn't. There was a mark on the glass, stained that made it look halfway up the glass. Once I got the top off the tank I found it was only half full, just over the suction strainer. I cleaned the sight glass with a Q-tip thru the little holes around the perimeter so it is all clear, then refilled the tank after cleaning the strainer, which was pretty much spotless anyway.

It's all back together and works just fine. Lesson learned, make sure you have a clean sight glass. Picture is before I cleaned it, with hardly any oil in the tank.

Cheers