Do you believe the viscosity and additives are consistent with the stated oil type, grade and trends?
The Calcium & Magnesium both show a marked change and are not typical hydraulic oil additives. What oils typically have these additives?
Engine Oils
Calcium and/or Magnesium are common additives used as part of the detergent / BN additive package to neutralise acids in engine oils.
Some typical Total Calcium + Magnesium values are as follows:
- Low ash oils - values can be less than 1500 ppm.
- Medium and high ash oils - values can be between 2000 and 5000ppm. This is the most common type of engine oil you will come across used in many cars and trucks.
- Marine High BN 4 stroke oils - values can be 20,000ppm+
- Marine Cylinder oils - values can be 40,000ppm+
Where might the Lithium be coming from?
Grease
Lithium greases are the most common greases as they have good "all-rounder" properties. Lithium in an oil sample is almost always from grease contamination.
Using your trending skills, what test has shown a marked increase and should have been flagged abnormal, but has not?
Water
Water has previously been less than <0.1%, but now has jumped to 0.9%. In a hydraulic system this much water can be severely damaging by the rust it can cause. More importantly water under pressures such as in a hydraulic system can boil, meaning sudden uncontrolled jerky movements. These movements can be a considerable safety issue.
Where is the chrome coming from? - Clue this is a mobile piece of hydraulic machinery
Chrome plated Rods
Chrome plated rods involved in articulating farm equipment attachments through the power of hydraulics. If you see the shiny metal on these machines, it is usually chrome plated.
What process is likely leading to the iron present in the sample when there has been no increase in ferrous magnetic wear?
Rust
As ferrous debris / PQ analyses measure the magnetism of the sample, they measure the large and small ferrous particles. So the increasing iron would be expected to see a slight increase in PQ if these are all magnetic particles. However, this has not occured suggesting the iron is likely not magnetic. The most common cause of iron being non-magnetic is it is in the form of rust particles. The presence of high water could be the cause of the high iron.
What would make you suspect that this is not just a badly taken sample?
There is wear present
The hydraulic oil sample shows evidence of grease, dirt and engine oil, which could be a badly taken sample. However, the sample shows high Chrome and Iron suggesting this contamination is in the machine.
Which diagnosis seems most correct?
Flush and change
The chrome (Technically, Chromium is the periodic table name, although most people abbreviates it to chrome) is unlikely to be linked to the the water and iron is more likely to be affected.
The ISO code has increased by 3, 3, 4 codes for the 4, 6 and 14 micron counts respectively, which since each code jump is doubling is just above an 8 fold increase. Visible debris will more likely be abrasive particles and promote more cutting wear than sliding wear.
The failure mode is unlikely to correct itself by itself and even with filtration the additives and viscosity would still be wrong afterwards, hence the recommendation to change, which is an unusual recommendation for a hydraulic system, but reflects how badly contaminated the system is.
