A good example of a bad example - the powerpack in question was
functioning for years, gradually turning the oil into the "what you see
on the pictures", up until one day the accumulator charging valve stuck
in "pressure limiter" mode. Although the equipment function wasn't
jeopardized (the necessary pressure was still there...) the oil
temperature got so high that the protective plastic cap on the valve
started to literally melt down,
before the wretched pump finally gave up. The sludge deposits are the
silent but indisputable proof of severe oil over-stress and breakdown.
