High copper ppm in excavator

The copper is high.
My experience is that copper alone (without the alloying elements Tin, Lead, Zinc) is not a very reliable diagnostic element. Copper can be derived from bearings (Cu/Pb), bushes (Cu/Sn), oil cooler leaks(v high Cu but with Na) or oil cooler corrosion/passivation (v high Cu).
Some very high copper results can appear after replaceement of oil coolers (large surface area of copper). Over time (perhaps 2-4 oil changes) the copper will be pasivated by the additive systems.
If the unit is running well and there is nothing to suggest a problem, continue monitoring to see if the copper is reduced over subsequent oil changes. I would be reluctant to take off sumps for inspection based on a single copper result; particularly as all other parameters are normal.
My recommendation is monitor the copper over a few oil changes and look for a decrease in copper.
Hope this helps. Col

The same problem is seeing in my area also.Here the excavator is Hitachi with cummins engine.The oil analysis report showing high copper (68 ppm) and lead (19 ppm).Is it due to bearing corrosion.The TAN is around 4 mgKOH/gm and the TBN is still more than 10 mgKOH/gm.What is actually oil cooler passivation.Is it same as the cooler core leaching.But cooler core leaching is a chemical process.

hi, i work with Kobelco excavators, daily.
i know excavators fairly well and i am a cert. hydraulic. tech..
this is a hydraulic oil sample.
hydraulic system.
copper can be coming form your piston hydraulic pumps, swing hydraulic motor, or travel hydraulic motors.
usually the likely one would be your hydraulic piston pumps' piston shoes.
they are brass.
what i suggest is isolate the different components case drain lines.
if the pump case has a case drain filter.
change it, and cut the old one open.
if you see brass with your naked eye and lots of it you have problems.

now, you have to watch, if you bought machine used you can be seeing signs of a previous failure.
it is hard to get all the hydraulic oil out of an excavator hyd system.
not going to happen.

also, copper is sometimes used as an additive in some oils.

your oil maybe mixed oils which if not controlled from day one owning the machine this is very possible.

how is the machine operating, that can give clues.

preventative maintenance;
hydraulic filters should be changed every 500 hours.
hydraulic oil every 2,000 - 2,500 hours.
the air breather filter on the top of the hyd tank at least twice a year.
hyd oil should be of mobile equipment (outdoor hyd oil w/ high viscosity index)
ie: ESSO UNIVIS N 32, HYDREX MV 36, ETC...

I would request an Aqueous Metals Test to see if the copper is dissolved or particulate. Copper that is leaching off a component will not show up in an Aqueous Metals Test. This might help you narrow down the source of the copper i.e wearing component (s).

Good Luck

IN ADDITION THE COPPER COULD BE COMING FROM THE PRESSURE VALVE PLATES IN ONE OF THE COMPONENTS I MENTIONED EARLIER.
AGAIN MORE THAN LIKELY FROM THE MAIN HYDRAULIC PUMPS.

Hi Getyourbone,

we have noticed the same High Copper reading in industrial Hydraulic system where the only Cu in the system is the heat exchanger, when checked by WDA there are no significant metallic particles present.
As the other replies state copper on it own has not presented to us any significant abnormal wear debris, being a fairly reactive metal when exposed to environments not ph neutral there will be enough "Dissolved" copper to lift the ICP results significantly but no significant wear debris when checked visually up to 1000X by WDA if Cu only is reading high.
Regards Rob S