Netstal HP1500/870 1990pd - Overheating!

Good day to everyone!

Please help!

Once we bought this Netstal. It was working fine with a small chiller and there was no problems at all.

But at one time everithing was changed - machine started to overheat very fast and we cant cool it even with much bigger chiller.
I dont really understand anything in chillers power but I know for sure that our thiller can handle 3 200T machines
but cant handle this one Netstal.

Also servo valves started to work unproperly:

- clamping/opening servovalve doesnt keep mold in one position and mooving plate moves slowly.

- loading servovalve (MOOG) - it seems to me that exactly this one heats the oil. Also hydromotor cant keep rotation level
to load 300grams of PS.

Servovalve photo attached.

I ask anyone who knows something about this machine or about moog servovalve to give me some advice!!

hi,
it looks, that you have a issue with one hydraulic valve in the circuit.
please check the valves with IR camera if is possible.
You have a oil heat up on it.
Valve is not fully closed.
It can be also on hydraulic pump.
Please check also all filters (suction, hi pressure, oil filter).

If i hear hissing in the valve does it mean something?

yes, if the machine is not moving, the hissing means oil leakage through valve. the oil is under pressure and it generete the heat (shear in the liquid)