Hydraulic Filter Magnet

[kcender]

I just changed the hydraulic filter on my B2620 and was surprised to find that it has no magnet.I asked the parts guy about it and he said they don't have a magnet.He said he only sells one model of Kubota brand hydraulic filter with a magnet,it is the one for my previous L3240 and other models as well.I have seen many instances of people on TBN finding metal shavings and residue on this magnet when they changed the hydraulic filter.I found quite a bit on the first change with my L3240.So why no magnet on the B2620?What is supposed to catch the metal residue from the machining of the cases?I looked in the owner's manual but there was no mention of a screen to clean.The manual doesn't recommend the hydraulic filter being changed until 400 hours but I changed it at 63 hours,just for peace of mind.I am now wondering about the metal shavings that I assume are still somewhere in my transmission.What have other Bxx20 owners experienced with this?Is there a screen and if so,where is it located?

 

[Chilly807]

If you cut the old filter apart, there will probably be some metal in the filter material. All the magnet does is trap the metal before it gets to the actual filter media. Maybe the B assembly line is good enough that Kubota doesn't see the need for a magnet on the filters.

I'm still finding a few machining chips on the third filter change on my L3400.

Sean

 

[gwdixon]

One of the things I did (and still do) with my BX2200 is to put a decent sized magnet on the metal outside of the oil filter. Harbor Freight sells them in several sizes. I don't know if it does any good but it seems like it should.

Once a cow magnet was taped to the filter with duct tape but it didn't seem to stay on very well.

 

[MHarryE]

Are magnets common on other manufacturers products? I ask because our other brand tractors don't have them, and in my 44 years of mobile equipment design I have never used one nor seen one used. I've only used magnetic plugs on gearboxes where we were not able to put a filtration circuit. It's not that it's a bad idea because any particle trapped before getting to the filter media extends filter life.

 

[kcender]

Thanks for the responses.I can see where the smaller metal particles would be trapped in the filter media.My concern is with the long curly spirals that are sometimes present.I have seen pictures of these that were so long that I don't see how they could get inside the filter.In that case they would still be moving around inside the transmission.I don't really know what is in my transmission but it makes me wonder.With a magnet these long pieces,if present,would be captured and removed with the filter change.

 

[oldnslo]

Down side of magnets is that can cause the smaller fuzz like particles to clump together and then get flushed down stream from a flow surge. I have seem them used on suction strainers but never on a pressure or return line filter.

Like HarryE stated,
Magnetic plugs are very common on gear boxes where no filtration is present.

 

[rScotty]

Down side of magnets is that can cause the smaller fuzz like particles to clump together and then get flushed down stream from a flow surge. I have seem them used on suction strainers but never on a pressure or return line filter.
Like HarryE stated,
Magnetic plugs are very common on gear boxes where no filtration is present.

Magnetic circuits are what I did at work, so I have some knowledge if anyone has questions. Although this posting might just be redundant as I agree completely with what MHarryE and OldnSlo just said.
If you add magnets, think it through carefully. Having one on the intake surface of the filter isn't going to do much. Anything that makes it there is caught anyway. Having a magnet on the other surface of the filter - the surface where the cleaned oil returns to the system - is pointless as the filter has already caught and removed particles of a size to be a problem.

As for those large curls of metal - I think we've all seen them and they frighten me too. It seems so "unKubotalike" not to flush the cases better. But what about all those the smaller chips? Take a look under magnification and see if you agree that some have crushed edges that look like they were squeezed off of a larger chip. Maybe during machining; maybe not. About half of them are blued from heat....what's that all about?

There used to be a line of aftermarket drain plugs that had magnets potted into the inner ends where they could pick up particles directly from the oil. BTW, simply placing a magnet on the outside of the drain plug does nothing. The idea of the aftermarket magnetic plugs with the internal magnets was that you would wipe off the fuzz when you pulled the plug out. Sure enough, they were often coated with fuzz. Cleaning them made me feel good, and I think there's a benefit there - but only if you pull the plug a lot because there's a problem that could happen when enough fuzz accumulates to saturate the magnetic field. In magnetic saturation, new particles attach to the fuzz ball at the expense of old ones which are knocked off - now free to circulate as little magnets themselves able to attach themselves anywhere they want and not be flushed through to the filter and removed.
After a lot of thought, I'm not in favor of the magnets unless they installed so that they can be serviced quite often - more often than one would normally change the oil.
To my mind it makes sense to change the filter more often than recommended in the first few hundred hours. I changed mine at 20, 50 and 100 hours. The oil itself is expensive, but it is easy enough to clean and reuse it several times.
luck, rscotty