DIY Oil Filter Cutter

[Frank S]

I agree that filter cutters are among the dew things which have gone down in price over the years. I cut most hydraulic filters open and examine the filter media for particulates. This tells me if there is something going on in the systems to keep an eye on if there are nonmetallic particles it is an indicator of a possible eventual seal failure. very fine particles in small quantities means the filters are doing their jobs and usually nothing to be concerned with larger quantities mean the filters should be changed more often. As equipment ages there will almost always be some metals in them. If particles are increasing in size and quantities, then it is time to start keeping a closer eye on things and change the filters more frequently. Browning or discoloration of hyd. oil can mean it is time for a fluid change and or overheating. large chucks of anything are an indicator of bad things to come. Possibly time to start doing pressure testing of the individual cylinders for internal leakages, large pieces of metal are always bad. an entire system can be at risk of needing a total rebuild and time to worry about the pumps motors and valves. Generally, when I would cut open a filter, I would send samples of the filter media to a testing lab since just sending an oil sample from a large system will not yield accurate results if I suspected something going on.
A lot of times when I change the engine oil in a truck, I will cut the filters open and inspect them rather than just sending an oil sample to a lab. I can often find things that need attention going on in an engine before the results come back from the lab.