In need of a education

Never having done any oil samples before I decided to send on in on my 5100 hour 279c hydraulic system. How does one determine if there is reason for concern or not ive done some reading on it but its still abit over my head. Thanks as always

In my opinion the key to using oil sampling is to do it every service and establish a good amount of data. That way when you compare numbers from previous samples and you notice one climbing or way high you can say, "ok, this is a change from normal so looks like we've got something going on here". The type of material will give you a better idea of where to look for the problem. Cat has a baseline of what are acceptable levels but the more sample history you have the better.

PS: if something was going on or you had high levels of something they would bring it to your attention on the sheet.

Oil looks good, overall. Except it's dirty.
With hydraulic oil, oxidation and the ISO4406 are key things to look at. Both look good.

The sample ISO is 22/18. That's 4 times more contamination than Caterpillar recommends for your machine, which is 18/15. ( I'm pretty sure about the spec, but I maybe off. I'm too lazy to look at the book).

Like 02DMAX says, it will take more samples to develop a base line to accurately trend. Three samples is the rule of thumb. I recommend a 500 hour schedule, or whatever the O&M says.

What to do about the contamination? If I was on the job, first I would check when the hydraulic filters were changed. Then, I would review service records. I see the oil has 55 hours on it. Maybe the new oil was contaminated or got contaminated? I would inspect all the hyd cylinders for leaks. If oil is leaking out, dirt is getting in. I would look at the hydraulic cap and the breather. If all that looks good, I would see if Cat has a clean-out filter for that machine. If so, I would run it for 50 hours, remove the clean-out filter and resample. Hopefully there is an improvement.

If no improvement, I would consider kidney loop filtration with a filter cart. My $.02

One thing I don't see in your snips is a value for Silicon (Si). That is a good indicator of the level of dirt in the system. Did you manage to cut it out.?

Viscosity is a bit on the high side. What are you using for hydraulic oil..? I'd normally expect the viscosity to be around 6.5 for an SAE10W hydraulic oil which for your location would be the OEM recommendation.

As others have said, a single oil sample isn't going to tell you much, oil sample analysis is all about looking for trends in wear metals, etc.

The only time a single sample result can be useful is in the case that you suspect the presence of water, glycol, or fuel in a system. In that case it will give you a confirmation that what you suspect is either present or absent.

Silicon is at 9ppm i did cut it out it current has mobil 424 in it for the reason being it was what I use in most all the hydraulic systems main reason for the sample was to try to see if something was about ready to explode due to not having any service history up to this point. I am going to take a close look at the breather on the tank to be sure it has no leaks to speak of other then the hydraulic quick couplings for the attachment. Thanks again

Silicon in double figures in a hydraulic system makes my radar spark up. 9ppm isn’t bad by any means.

Nige said:

Silicon in double figures in a hydraulic system makes my radar spark up. 9ppm isn’t bad by any means.

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Would it be safe to say I'm in the clear on the metal readings also?

It’s hard to say with only 55 hours on the oil. The wear tables are most often written on the basis of 500, 1000, or 2000 hours on the oil which is the point at which it would normally be changed. TBH the best thing you could’ve done would be send a sample of the oil that was drained 55 hours ago. That would have been a much better indication of the overall health of the system.

Ok I guess in about 2 or 3 years ill take another and see it only sees about 60 hours or so a year.

Tyler d4c said:

Ok I guess in about 2 or 3 years ill take another and see it only sees about 60 hours or so a year.

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Sorry. I'm used to machines doing 500+ hours a month.

Having had a closer look your numbers indicate nothing obvious in the wear metals category.

Going back to the ISO Code, I've cut & pasted your numbers regarding the 3 categories where the measured 22/18/14 ISO Code was determined (4, 6, & 14 microns) in order to make a bit more sense.
ISO 22 - 20,000-40,000 particles/millilitre.
ISO 18 - 1,300-2,500 particles/millilitre.
iSO 14 - 80-160 particles/millilitre.

The one number that I'd personally like to see lower is the 4-micron range. For long-term component longevity I'd like to see it as either ISO 19 or 20 (between 2500 & 10,000 particles per millilitre). To achieve that I would suggest a change from the standard 1G-8878 filter element for the hydraulics to a 102-2828 High Efficiency element. It's a direct replacement. The HE element should do a good job of reducing the level of particles in the 4-micron range, and also in the other two ranges also.

Well said, Nige. Good explanation of the ISO.

I'll get one of those filters on the next parts run hopeful I can keep this thing working for idk the next 20 years thanks again.

If you do get one of those HE filters give it a couple of months to have some sort of effect and then take another sample.

Don’t forget to take a sample of new oil at the same time. The results of the ISO on “new clean” oil might amaze you.

@Tyler d4c , thanks for starting this thread. I've learned so much from the contributors that shared their knowledge that I know I need to go sample my bobcat now. If nothing else but for peace of mind and awareness.

It will probably be a year or better till I can return with any response no earth work is lined up for the year yet

Here's some more background to the ISO Code and what it means/how it is measured.

102-2828 updates to 4656502

Sorry, I only looked at the Parts Manual. Never checked to see if there was an updated P/N. Believe it or not but the HE element 465-6502 is actually cheaper than the "standard efficiency" 1G-8878 element. Riddle me that if you will ...........

I have an interesting presentation regarding Contamination Control but it's too large (17Mb) to post as an attachment here. If anyone's interested send me a PM with an email address and I'll gladly forward you a copy.

Nige said:

Sorry, I only looked at the Parts Manual. Never checked to see if there was an updated P/N. Believe it or not but the HE element 465-6502 is actually cheaper than the "standard efficiency" 1G-8878 element. Riddle me that if you will ...........

I have an interesting presentation regarding Contamination Control but it's too large (17Mb) to post as an attachment here. If anyone's interested send me a PM with an email address and I'll gladly forward you a copy.

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I'll pm you my email please and thank you I never could understand why they just can't make one filter would it ever hurt to not just use the ultra he.