Hydro Filter Change Only

JimmyJazz said:

I had a BMW motorcycle I bought new in 1991 that I obsessed over maintaining. The oil filter was a pain to replace and occasionally I would change the oil and not the filter. When I told this to James at the dealership he said it was like "Changing a diaper and not wiping the rear". This altered my perspective to this day.

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Yep.. I’ve never ever changed a filter and not the oil or the oil and not the filter. Doesn’t make sense to me. James was right!

Each to his own, I guess... but I can’t help but think most people who use a vacuum don’t understand the construction of the spin-on filter.... because the vacuum reverses the impetus of oil-flow... applying suction to the oil in the dirty-side of the filter.

As for whether or not to change a filter and not oil.... or change oil and not filter: It makes no sense to me to run clean oil thru a dirty filter which might already be in by-pass mode.. Until that filter is cut open and examined (which 99% never do) it is not known the filter condition (Dirty or in by-pass)

Sooo.... it seems to me that it’s a one-way-street..... It’s OK to change a filter without an oil change...but not the reverse.

And each model machine has it’s own Maintenance Schedule which should be followed. For example, the M4700-M5400 series changes the HYD filter every 200 hours with no fluid change, and changes the fluid and filter at 600 hours. NO chronological filter or fluid change is required. That’s clearly different than other models. READ your manuals.


PS: I admit I do not follow the advice on external hoses, I only inspect and replace as necessary.

GeoHorn said:

Each to his own, I guess... but I can’t help but think most people who use a vacuum don’t understand the construction of the spin-on filter.... because the vacuum reverses the impetus of oil-flow... applying suction to the oil in the dirty-side of the filter.

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Your assessment is wrong. In a static system there will be no pressure differential at the filter media hence there will be no flow of oil either way through said media.

whitetiger said:

As I have stated several times before, the HST filter on an L series tractor is a pressure-fed filter. You can take the filter off and only lose less than a cup of oil, no matter how long you have it off.
The suction filter is the one that you lose a lot of oil changing, but you change it at the same time as the hydraulic oil.

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Definitely on L series very little oil lost !!

ruger1980 said:

Your assessment is wrong. In a static system there will be no pressure differential at the filter media hence there will be no flow of oil either way through said media.

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Re-thinking on this... you are probably correct that no actual oil flow will likely occur since (in addition to a closed system) the filter has an anti-drain-back/ back-flow preventer in most cases.

whitetiger said:

As I have stated several times before, the HST filter on an L series tractor is a pressure-fed filter. You can take the filter off and only lose less than a cup of oil, no matter how long you have it off.
The suction filter is the one that you lose a lot of oil changing, but you change it at the same time as the hydraulic oil.

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At 50 hrs I changed Transmission filter and Hydraulic filter very little fluid loss maybe 1 quart ?? Had filters ready to go there easy to access !!! L4701

I follow my B2650 manual's maintenance schedule.

So replaced the HST and sump filters, and engine oil & filter @ 50 hours service , then only the HST filter at 200, along with the engine oil and filter, as per maintenance chart.

I got set up at 50 hours with new hst filter lubed and ready, and a quick spin off of the old then quickly spin on the new sump filter. No jacking the tractor, so vacuuming, just act quickly, with the verified correct filter lubed ready to go. I lost maybe 1 litre of hydraulic oil before the new filter got tightened on. There was no sign of metal shaving or particles on or in the old filter, which I was advised to inspect when I changed it. Take pics of any such signs so if there's any warranty issue later there's a possible clue.

The sump filter I did replace again along with the Premium UDT oil at 400 hours.

Why would Kubota say no udt fluid change until 400 hours if there was any reasonable chance that leaving it for 400 hours, with required filter changes, would be at all risky for the tractor's hydraulic system?

And just my opinion, backed by remarks from my Kubota service manager, is that the specs Kubota publishes for their tractor maintenance schedule has pretty much a 100% fudge factor. In other words, all the fluids and filters could run twice as long as specified under average operating conditions and still effectively run and protect the machine without significant power, functionality, or wear longevity losses.

Just my opinion. No judgement of those that see a need to do the "400 hour" or full change of fluids and filters at 50 hours. That's obviously your prerogative and won't hurt anything but your wallet and add likely good oil to the recycle pail.

Again, in IMO, and Kubota's, unnecessary.