Oil & Fuel Kubota L45 hydraulic fluid maintenance

   #1  

Captain Dirty

Gold Member
Joined
Jun 29, 2016
Messages
404
Location
Eastern Mass
Tractor
Goldoni 600, Kubota L45
My Operator's Manual states that the hydraulic fluid, the transmission oil filter (HST), and the two hydraulic oil filters should be changed every 400 hours. Many on this forum state they have heard, from purportedly reliable sources like dealers, that the oil "never" needs to be changed, just the filters. I am in a subset of that group that expects never to see that advice in writing from an authoritative source, especially a dealer who has an interest in selling more fluid. My L45 has a capacity of 46 liters, over 12 gallons, and Super UDT2 is over $25 per gallon.

At a cost of $28 I sent a 400-hour sample for analysis explaining my intentions of changing filters only. The notes on the analysis report stated: We'll help you get the most out of this fill of hydraulic fluid. . . No moisture or dirt was found, and the lack of insolubles show minimal oxidation. This oil is ready for more action, so just grab a sample when the next filter change is due . . .

I felt justified in changing filters only, but needed an elegant way to do so. The 50-hour service had specified changing the filters only, and I had been led to believe dealers changed the filters without draining, reinforced by the manual's instructions to "Quickly tighten the filter. . ." Also I did not have 12+ gallons of clean containers to hold the fluid for re-use. The change of the horizontal, transmission filter was not too bad, but the vertical filters gave me a bath. In my haste to re-install, I distorted a gasket; the bath continued. Top-up after filter change was about 3-1/2 gallons.

Several have suggested using a shop vac to hold the fluid while the filters are off. Reports on the process ran from "I didn't spill a drop" to "sucked fluid into the vac, nearly had a fire, and never again". I have never changed a filter, even after draining, without spilling a drop, so that report was suspect. But enough reported success that I decided to try the shop vac.

The full mark on the dipstick is several inches below the fill port indicating a fair amount of headspace, so I thought it unlikely the vac would suck up fluid. None the less, I spent about $10 at a box store on 2' of 1" clear plastic hose, a barbed fitting that threaded into the fill port, and 2 hose clamps. While I changed filters I had an assistant hold the shop vac nozzle in a funnel at the top of the hose with instructions to regulate the suction by lifting the nozzle from the funnel so any fluid stayed in the hose. No fluid entered the hose; I did hear gurgling when the filter seals were broken indicating the vac was sucking air. Leakage was minimal. Top-up after the change was about 3 quarts which was consistent with the amount caught in a pan (including fluid from the filters themselves).

So I spent about $63 and saved $300. Hopefully others may find this info helpful. Oil analysis may save the cost of the oil you would change; a little plumbing and a shop vac may save spilling the oil you saved.
 

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   #3  

nyone

Platinum Member
Joined
Jan 31, 2012
Messages
720
Tractor
Ford 851
Man talk about penny wise dollar foolish. New that l45 was what $40,000?

Save $300 today and buy a new hydrostatic pump in the years down the line. Hey are very expensive to repair and almost make the tractor have no value when they need to be replaced. I would never skip the first service on any new piece of equipment.
 
   #4  

MechanicalGuy

Gold Member
Joined
Jun 24, 2019
Messages
421
Location
Beautiful South
Tractor
Kubota mx5200
Great info. Thanks.

I've decided I'm going to do my filter changes when the temp is about 15*F outside. The oil should be so thick it won't dare leak out.
 
   #5  

MechanicalGuy

Gold Member
Joined
Jun 24, 2019
Messages
421
Location
Beautiful South
Tractor
Kubota mx5200
Man talk about penny wise dollar foolish. New that l45 was what $40,000?

Save $300 today and buy a new hydrostatic pump in the years down the line. Hey are very expensive to repair and almost make the tractor have no value when they need to be replaced. I would never skip the first service on any new piece of equipment.

It's actually quite the boondoggle to change oil at 50 hours in a non-combustion non-break-in situation when the filter can be so easily changed. I understand why people do it, but it's not necessary by even the most strict scientific curriculum. I can't think of a single valid reason to dump out gallons and gallons of hydraulic fluid out of a perfectly functioning hydraulic system.
 
   #6  

fried1765

Super Member
Joined
Jan 6, 2015
Messages
9,380
Location
Northeast & FL
Tractor
Kubota L48 TLB, Ford 1920 FEL, 8N Ford, Gravely 12 HP "Professional", 48" SCAG Liberty
It's actually quite the boondoggle to change oil at 50 hours in a non-combustion non-break-in situation when the filter can be so easily changed. I understand why people do it, but it's not necessary by even the most strict scientific curriculum. I can't think of a single valid reason to dump out gallons and gallons of hydraulic fluid out of a perfectly functioning hydraulic system.

Seems like an obviously very valid point!
Is there a downside that I am missing?
 
   #7  

RickB

Super Star Member
Joined
Sep 18, 2000
Messages
13,949
Location
Lincoln County, NC
Tractor
Just a Scag
Man talk about penny wise dollar foolish.

Save $300 today and buy a new hydrostatic pump in the years down the line. I would never skip the first service on any new piece of equipment.

Oil scans done by reputable labs do not lie. Oil scans are bar none the best way to get the most from oil investment.
What you do is your business but your criticism of oil analysis is unfounded.
 
 
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