RC4WD Excavator

[CustomRCmodels]

Hello Joe ,
Why I am not surprised that you are the first one of us here having one of these , ha .

I haven’t messed with model-hydraulics ( not yet ! ) ,
but that weird loud noise , besides that it seams like that the pump is working hard ,
is probably a result of to much play in the internal components of the motor and pump .
Precision is what costs money , therefore I am assuming they used relative large tolerances in manufacturing of these pumps .
To tide tolerances would make it sees up after a while , to large tolerance just make everything more loose , therefore more noise .
That would be my guess on that .

As for damage via the leaked out oil to the electronics , oil is an electrical insulator ,
therefore I doubt that you did get any damage out of that ,
except of the chemistry of that particular hydraulic oil.
I came across some ball-bearings from China which had a grease-filling which eat up plastic ! You may could see over time that some plastics or rubber get damaged ,
which again I doubt , since hydraulic components hold all kind a seals and such made out of plastics and rubber , would be kind a dumb having a hydraulic-oil with such damaging ingredients ?!