Iseki TU1700F hydraulics

[Chris0901]

I have a problem with the hydraulics on my Iseki TU1700F. When the oil gets hot the rear lift will not work. From cold it all works fine.
I have replaced the oil with SAE80 as specified, flushed out the gearbox and gauze filter, stripped the pump and inspected for wear, removed and cleaned the whole of the hydraulic valve body...Cheked the relief valves for wear or debry. I have also replaced the piston seal.
Has anybody had the same problem? What's the solution?
Chris in Spain.

 

[fxrs55]

When you had the pump apart did you replace the shaft seal?
Also maybe the spring on the relief valve is weak and when hot
its not holding valve closed. I have had the pump shaft seal
go bad on my TX1300F and it would suck in air and foam
the oil until it over flowed.