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.
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.
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.
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.
Tyler D4C, Why not just use a HE filter all the time? Damn good question. You are a quick study. My students would ask that question about half way through my contamination control class. Quick answer is the design of mobile hydraulic systems, especially on compact equipment is always a compromise for space. Reservoirs and filters are made smaller than standard best practices to make them fit on the machine. Of course, cost is an issue, too. The HE (clean-out) filters plug up very fast in normal ops. 50-100 hours, instead of the normal 500 hour change interval. The manufacturer could install a super efficient filtration system, but the filter assemblies would be huge and costly. Compact equipment is built to a price point in that highly competitive market. Plus, there is some planned obsolescence built in to keep the parts and service departments busy.
Problem with using HE filters as standard elements is that unless you feed the machine with clean oil on PMs the filters may plug up quicker than normal. That is something you have to live with until the system cleans up, and is the reason why some folks prefer standard elements - to avoid the hassle of having to change them outside PMs on the odd occasion. i assume that your machine has a plugged hydraulic filter indicator light..?
I'm not sure I'd agree 100% with that, with the caveat that "Not if the oil's clean in the first place they don't". The location I've been working recently has a filtration plant for all their oil grades apart from engine oil. Hydraulic oil comes out of the guns in the shop at ISO 14/9 or better. They use HE filters as the standard element and under those conditions the filters will quite happily go 500 hours between changes under normal circumstances. I would say on this machine and bearing in mind the hours it works Tyler is most likely going to be doing 6-monthly or annual filter changes rather than hours-based. Under those circumstances I'm confident HE filters will work for him.
I believe it does
You'll need to keep an eye on it, especially in the early days. I just sent you an email BTW.
I got it im sure the alarm in the cab will be singing also. I'll be reading up on that email this evening im just about to leave to a power plant to do some work on a belt line. This day job always in the way of fun.
The issue in my eyes with the HE filters is that a dirty system will plug up the filters and allow the bypass to open letting the return oil go around the filters. The bypass valves are just springs on a poppet that open when differential pressure between the inlet and outlet get to a certain point. The springs have no adjustment and the differential changes as the system heats up. Many machines have a pressure switch installed across the filter but it only tells you when the pressure difference is high. It doesn't really tell you if the bypass valve has opened. If your system is clean, the standard filters are just fine. If you have had a failure, then the HE filters will help get the small stuff out of the system. If you have a problem with silica in the system, you have the issue of how it got in there and an HE filter will do you no good until you find that source and correct it. Not to be nitpicker but I believe the molecule described in oil sample reports is silica and not silicon. Silica is basically dirt with quartz. Silicon is a similar molecule with different properties. Check out the link for a better explanation. https://www.differencebetween.com/difference-between-silicon-and-vs-silica/
Hence my question did Tyler have a plugged indicator for the hydraulic filter on that particular machine. There is a likelihood that the first HE filter might plug within a short time. Another valid point here would be to question if hydraulic oil was being added/topped up on a regular basis on the machine. Because if oil is leaking out then dirt & contamination is pretty much certain to be getting in. Then it's a case of fix the leaks first before trying to clean up the system. I suspect the answer will be "No" because @ 9ppm the silicon number is way too low to have any major sources of entry of dirt into the system. It would need Si to be greater than say 20 or 30 to indicate significant dirt entry. I was always under the impression that, because the chemical symbol "Si" is used on the analysis reports, that it was referring to Silicon the element rather than Silica the mineral. However I have no proof of that - need to investigate further. It might be worth mentioning that because Silica is chemically Si02 (silicon dioxide) then silica should still show up in an analysis report under the "Silicon" heading because it is silicon-based.
According to Page 3 of the attached it is silicon, or appears to be so to me.
I may be wrong here but most of the systems I've come across the switch was a mecahnical one operated by the poppet when the filter went into bypass. On the smarter machines with VIMS the plugged filter alarm would not go off until the oil temperature went above a certain value even if the element went into bypass.
Like I think I mentioned before the only leaks I know of are the quick couplings maybe be a silly idea but why couldn't a fella put a second base on after the HE filter with the standard element for if and when the bypass opens
Keep an eye on the plugged filter indicator would be the easiest IMHO.
This is true just a idea may be good for some application. Over kill for this tho
I was thinking of using a standard filter first and then the HE filter. That way the big stuff will e caught in the standard filter and not plug up the HE as quickly.....But what do I know
I don't think I've seen a pop up type indicator on any of the smaller machines I generally worked with. All the excavators, loaders and dozers I've put my hands on have the light on the dash but no connections to the poppet valve on the top of the filter whatsoever. The bypass is that plastic thing you remove from the top of the filter before you pull the filter out of the can. I have no doubt that the mining industry in the two hundred ton machine and higher has the profit margin to install quality. It isn't the same in the construction and logging industry. Those bypass lights come on every morning when the temps drop below 40 degrees F. Even the filter carts I've worked with have the two colored ball to indicate restriction in the filter. A high efficiency filter in those will plug up pretty quick on a dirty system. I also have a couple of clients now that are permanently installing kidney loop systems on all their hydraulic systems. Some companies are big into oil sampling and dumping the machine when an accountant says to do so. The sampling in my mind is just a waste at that point. Others are just keep on keeping on and deal with issues when they come up. In my experience, once you know you have clean systems, do the factory recommended maintenance and you will be just fine. I agree that silicon might be what the spectrogram sees on an elemental level but the oil labs all told me over the years that silica is the damaging substance. It is the indicator of dirt entering the system. I have run into people calling it silicone as well.
This is great discussion. Good stuff, Gents. Thoughtful posts. I don’t believe there is a filter indicator on this machine.
The base has a sensor of some kind in it must just turn the light on when the pressure is high
What do they charge for an analysis?
15 or 20 bucks at the local dealer