New(ish) Kubota M62 With Filthy Hydraulic Oil

[CalG]

Thanks everyone for the excellent advice. Please excuse the delay responding – I’ve been busy changing the fluid.

Additional Information:

Tractor was purchased new from dealer– no previous owners. Unfortunately it looks like we chose a bad dealership. He is refusing to help. Called Kubota - they say its between use and the dealer.

All maintenance done at the suggested hours.

No use of hydraulically driven attachments.

We’re very careful with the cleanliness of the hydraulic connectors when taking the backhoe off/on.

Tractor get used every other day or so – always to recommended temperature.

Tractor is housed in a barn – but we do wash it frequently.

Sizzle test for water is between negative and 0.05 - 0.1% 500-1000 ppm. It was zero with Blackstone.

Again – thanks for the help.

Did you get it from Pinnacle View?

eta
Dang! This thread makes me feel so guilty. I've got a Kubota B7200 hydro that I doubt has ever seen a trans. fluid change. I know the filter is original (by looks)
I've got well over $400 into it (came free with a snow blower I wanted. I've only had the B7200 for five years. Maybe I should clean the filters or something. Darn thing works great, I'ld hate to jinx it.

;-))

 

[5030]

My final comment (before I disown this thread is).... Never buy any tractor from an out of state dealer, always buy local even if it means paying a bit more and I think you are being a bit paranoid about something that is proving to be inconsequential.

I'm done, Good day.

 

[rScotty]

All along I keep wondering if the 'cloudiness' in the fluid is actually suspended air? Something I've never encountered but then I let mine sit (and cool off) for a while before changing the fluid or filters. Dang filters can be hot and so can the drain plug(s) and I'm a puss so I let everything cool off first. Not stone cold, just cool.

Right. We still don't know that the cloudiness wasn't normal entrained air, and that the particles were not simply normal manufacturing debris which would be eventually removed by the filters.

The oil analysis doesn't even compare their analysis with an unused sample. That's analysis 101.

All we have is one example tractor, a worried owner, no science, no comparisons, and much speculation built on a very little info.

Maybe that's just as it should be. I enjoy my TBN time as a discussion forum for hobbyists, not a technical forum for science geeks.

 

[Smokeydog]

If entrained air is a symptom might explain how dirt might be getting in. Possible original assembly issue?

Lot of Kubota B26s were made for many years with a rubber elbow on the suction side of the hydraulic pump that would prematurely fail. Poor design often would lead to it cracking letting air in. Some to the point of volcanic expulsion of hydraulic fluid out the fill and vent when hot. Mine never leaked at the elbow enough to spot the floor but did collect oily dirt. Air was being pulled that oily dirt from those cracks. Kubota has redesigned that line and sold the whole new line assembly for the cost of just the rubber elbow. Took 8 years. Never any recall.

I would check any rubber connectors on the hard suction lines. Rubber unions are often used to make assembly and disassembly easier and allow for some miss alignment. Make sure the clamps are behind the rolled barb of the hard line and tight. WSM might be hard to show where a parts diagram might show more clearly. Hard lines usually use a O-ring at hard connections. Any connection that has oily film of dirt is suspect of possibly air inleakage.

Woodlot use is hard on any tractor. Often have to make special armor to defend against sticks. Sticks seem to know where the tender spots are.

 

[rScotty]

If entrained air is a symptom might explain how dirt might be getting in. Possible original assembly issue?

Lot of Kubota B26s were made for many years with a rubber elbow on the suction side of the hydraulic pump that would prematurely fail. Poor design often would lead to it cracking letting air in. Some to the point of volcanic expulsion of hydraulic fluid out the fill and vent when hot. Mine never leaked at the elbow enough to spot the floor but did collect oily dirt. Air was being pulled that oily dirt from those cracks. Kubota has redesigned that line and sold the whole new line assembly for the cost of just the rubber elbow. Took 8 years. Never any recall.

I would check any rubber connectors on the hard suction lines. Rubber unions are often used to make assembly and disassembly easier and allow for some miss alignment. Make sure the clamps are behind the rolled barb of the hard line and tight. WSM might be hard to show where a parts diagram might show more clearly. Hard lines usually use a O-ring at hard connections. Any connection that has oily film of dirt is suspect of possibly air inleakage.

Woodlot use is hard on any tractor. Often have to make special armor to defend against sticks. Sticks seem to know where the tender spots are.

For folks just getting into hydraulics, only a leak in the piping to the inlet side of the hydraulic pump will pull air into the hydraulic system. Air is sucked in and "entrained" into the fluid by the pump rotor just like a kitchen blender making a smoothie. Air entrained in hydraulic oil makes the oil look cloudy or murky - but it clears up after the fluid sits for a few hours and cools off.

So suction side leaks are harder to spot. If there is a leak ianywhere after the pump pressurizes the fluid then it is easy to find because it oil leaks out.
But on the inlet or suction side of the pump there is no convenient leak to spot. Air goes in, & carries dirt with it, but fluid doesn't alway leak out. The main hint is the cloudy hydraulic fluid.

Just to farther confuse the issue, the hydraulics will work fine with some entrained air in the fluid. In fact, some air after a rebuild or fluid change is normal. You will see entrained air in the fluid for hours because that is how an open hydraulic system is supposed to work. It is how the system purges itself of trapped air bubbles. They entrain into the pressurized fluid and then are vented out when you shut down and the fluid cools.

All of that is simply repeating what SmokeyDog just said. It is why the suction side fittings and pipes are very first thing any mechanic checks when looking at a hydraulic system. It's where most of the age, damage, poor assembly, or owner related problems show up first. Most commonly it is a loose connection or old hose. Sometimes it is a spin-on filter not sealing. Also, some tractors have a cleanable screen in the transmission sump that is also part of the suction path.
enjoy,
rScotty

 

[Smokeydog]

For folks just getting into hydraulics, only a leak in the piping to the inlet side of the hydraulic pump will pull air into the hydraulic system. Air is sucked in and "entrained" into the fluid by the pump rotor just like a kitchen blender making a smoothie. Air entrained in hydraulic oil makes the oil look cloudy or murky - but it clears up after the fluid sits for a few hours and cools off.

So suction side leaks are harder to spot. If there is a leak ianywhere after the pump pressurizes the fluid then it is easy to find because it oil leaks out.
But on the inlet or suction side of the pump there is no convenient leak to spot. Air goes in, & carries dirt with it, but fluid doesn't alway leak out. The main hint is the cloudy hydraulic fluid.

Just to farther confuse the issue, the hydraulics will work fine with some entrained air in the fluid. In fact, some air after a rebuild or fluid change is normal. You will see entrained air in the fluid for hours because that is how an open hydraulic system is supposed to work. It is how the system purges itself of trapped air bubbles. They entrain into the pressurized fluid and then are vented out when you shut down and the fluid cools.

All of that is simply repeating what SmokeyDog just said. It is why the suction side fittings and pipes are very first thing any mechanic checks when looking at a hydraulic system. It's where most of the age, damage, poor assembly, or owner related problems show up first. Most commonly it is a loose connection or old hose. Sometimes it is a spin-on filter not sealing. Also, some tractors have a cleanable screen in the transmission sump that is also part of the suction path.
enjoy,
rScotty

Good wordsmithing, good explanation.

 

[mtputney]

Usually there is a narrative with the Blackstone result that gives an explanation for things that are out of range. When your insolubles were way high last year, did Blackstone give any explanation of what might cause that?

Blackstone says that things seem to be going in the right direction and to just change the filters...

 

[mtputney]

For folks just getting into hydraulics, only a leak in the piping to the inlet side of the hydraulic pump will pull air into the hydraulic system. Air is sucked in and "entrained" into the fluid by the pump rotor just like a kitchen blender making a smoothie. Air entrained in hydraulic oil makes the oil look cloudy or murky - but it clears up after the fluid sits for a few hours and cools off.

So suction side leaks are harder to spot. If there is a leak ianywhere after the pump pressurizes the fluid then it is easy to find because it oil leaks out.
But on the inlet or suction side of the pump there is no convenient leak to spot. Air goes in, & carries dirt with it, but fluid doesn't alway leak out. The main hint is the cloudy hydraulic fluid.

Just to farther confuse the issue, the hydraulics will work fine with some entrained air in the fluid. In fact, some air after a rebuild or fluid change is normal. You will see entrained air in the fluid for hours because that is how an open hydraulic system is supposed to work. It is how the system purges itself of trapped air bubbles. They entrain into the pressurized fluid and then are vented out when you shut down and the fluid cools.

All of that is simply repeating what SmokeyDog just said. It is why the suction side fittings and pipes are very first thing any mechanic checks when looking at a hydraulic system. It's where most of the age, damage, poor assembly, or owner related problems show up first. Most commonly it is a loose connection or old hose. Sometimes it is a spin-on filter not sealing. Also, some tractors have a cleanable screen in the transmission sump that is also part of the suction path.
enjoy,
rScotty

Attached is a picture of the fluid left in a jar for a few months – as you can see, there’s a whitish sediment layer at the bottom…

 

[5030]

That isn't much at all in reality.

 

[5030]

Kubota has redesigned that line and sold the whole new line assembly for the cost of just the rubber elbow. Took 8 years. Never any recall.

I need to check my M9's as both have the rubber hose that to my knowledge has never leaked but I'll check with my dealer and if the refit is reasonable, next time I change the fluid (which will be in the fall), I'll replace both. I'm sure my dealer will be aware of it. Being a 2002 and a 2000 models, doing pretty good I'd say.