I have a John Deere 120d, the hydraulic filter alarm comes on until the machine warms up. Even on days when the outside temperature is in the 90's. It only does it when I swing the dipper away. Sometimes when I uncurl the bucket. I've replaced the filters and it quit for a short time then started doing it again. It operates fine, the warning light just comes on. Any ideas? Thanks
Welcome to HEF sbleifus ! Maybe a bad filter restriction switch?
Are you using OEM filters?
Yes
Thanks for the reply.
How does your hydraulic oil look?
When you replaced the hydraulic filters did you cut the old ones open to check for the presence of particles in the filter.?
I changed it when I changed the filters. It looks clear.
I didn't, but I still have the filters. I will do that.
It just seems odd to me that it only does it when I push the dipper away. I have even tried multiple functions at once to create higher flow, still doesn't come on unless I push the dipper away.
I changed the fluid when I changed the filters.
At least if you cut the filter and inspect the media you can be absolutely sure whether or not there is anything in the oil. If you haven't done this before this VIDEO may give you some guidance. I know it is an engine oil filter in the video but the principle is the same.
Thank you!
Confirm from my parts picture that the filter switch is in fact installed. That filter switch was an option, not standard equipment on those machines.
If the switch is not installed what exactly triggers the plugged filter light.?
Please supply a serial number of the machine. I am assuming the switch option is installed and that the culprit might be a faulty switch. If the option is not installed, then I have to put on my thinking cap. Not enough caffeine yet for that . The OP mentions it only happens when the arm out function is actuated. That would be a function that would require the most flow, which in turn could activate a sensitive switch, unless the wrong viscosity oil was used. What oil did you use?
I should have provided all the information to begin with. After I purchased the machine, I realized it had the wrong fluid in it. I gathered a lot of information from this site and decided to go with Powerflow NZ 46. I wasn't able to completely drain the system, so with the advise of a couple local hydraulic mechanics, I drained all I could and refilled the tank. I repeated this process 3 times each time with new filters. The place I bought it from was a reseller and I wasn't able to contact the original owner to know for sure what fluid he was using. I used the machine for approximately 15hrs between replacing fluid and filters each time. The best i could gather was the fluid in it when I purchased it was a mixture of John Deere/Hitachi EX46HN and AW46 regular hydraulic fluid.
I wasn’t aware that JD excavators required the use of zinc-free/ashless hydraulic oil. Not that I am saying that’s the cause of the plugged filter alarms though.
Yeah, my understanding is Hitachi built John Deeres excavators. The manual and tag on the tank both say use zinc free.
When you drained the hydraulic tank did you notice a caramel candy appearing substance on the inside tank walls. You may not have noticed this but i bet it was there. When the 46HN has had regular hydraulic oil added to the reservoir and it doesn't take much a chemical reaction occurs that rapidly degrades the lubricating ability of the oil. This causes excessive pump wear sticky valves etc. I encountered this problem on a Deere 160DLC that would not boom down sometimes was worse in cooler weather was very random the boom load holding valve was sticking but on disassembly could fine nothing wrong, but the oil on valve felt gummy. After consulting with Deere DTAC I flushed the system three times along with filters and the problem never returned. You may want to pull a hydraulic oil sample and have tested to confirm if you need to flush system again. But i thank three flushes that you stated should be ok.
Thank you for that info. Do you consider a flush emptying the hydraulic tank and refilling or completely flushing the cylinders, hoses and motors? Could you tell by a physical examination of the fluid in the tank? Thanks again.
It should be easy to tell from an oil analysis if a hydraulic oil with a zinc-based anti-friction additive was ever used in the implement system from the zinc level (ppm) in the analysis result. Generally an oil with a zinc-based additive will come in at around 500ppm, but a mixture would be way less than that. IMO a zinc figure anything over 10ppm would indicate a deviation away from the recommended zinc-free hydraulic oil at some point.
If my memory serves me correctly, drain reservoir changed filters and run unit for a couple hours between flushes I spent an 8-hour day doing this. If you want to be sure after running unit a couple days pull an oil sample and have it checked for cross contamination, they should be able to tell the percentage of contamination.
Thanks so much. Sounds like i need to do an oil analysis.
Thank you very much. I'll get an oil analysis done.