How much hydraulic oil do i need in our M59?

[inner island coho]

Hi everyone,

I'm brand new here.

My land partners and I got a new M59 with a backhoe and I've been doing the maintainence on it (but I'm new to tractor maintainence). I drained the hydraulic oil for the 400 hour servicing and have now refilled it. The manual says the machine takes 45L of hydraulic oil, I put in about 30L but now when I check the dipstick it shows way over the max line (I let it settle and ran the engine and used the hydraulics to fill the lines already). I feel like I should go with what the dipstick says, am I right? Do I need to drain some of the oil?

Thanks for any advice.

 

[ManAtArms]

Where did you drain the oil from? Did you change the filters as well?

 

[inner island coho]

i drained the oil from the largest plug towards the backhoe. I did change all the hydraulic filters as well.

 

[inner island coho]

another simple question, does the engine oil sit in two separate oil pans (the reason there is 2 drain plugs on the engine?). and does the hydraulic oil sit in multiple separate pans, or is it all in one? if its all in one why is there multiple drain plugs?

 

[rScotty]

another simple question, does the engine oil sit in two separate oil pans (the reason there is 2 drain plugs on the engine?). and does the hydraulic oil sit in multiple separate pans, or is it all in one? if its all in one why is there multiple drain plugs?

I think it's a single engine oil pan, but that it droops down on both sides of the front drive shaft. Like an old motorcycle fuel tank with taps on both sides. So...yes, there are two engine oil drain plugs.

The hydraulic oil mystified me at first. My owners and shop manuals both show photos of two drain plugs for the hydraulic fluid, but like several other M59 owners I only found one drain plug. It's the big obvious one close to the middle of the tractor and right where a drain plug ought to be. Mine takes about 45 liters/12 gallons with the three filters changed too. I buy two 5 gal buckets and one 2.5 gal. plus three filters. And it costs! Last time I had a heck of a time getting the old filters off. Shouldn't have put them on so tight.

Bluing the bottom several inches of the dip stick by heating it in the kitchen stove burner flame sure has made things more readable. Now there's something really worth doing. It is a big improvement, costs nothing, has no negative impact, and doesn't even take any effort. And it's applicable to every Kubota on the market. Mentioning this is my own personal test to see if Kubota is listening in on this forum. As a design engineer I know I would be.....

There's about a quart left over from the 12.5 gallons after draining and doing the 3 filters. Must be quite a bit left in the hoses and hydraulic cylinders, but it simply stays there.

I've changed mine now several times during what I consider break in.....but will probably leave it alone for the next 600 hours or so. To my surprise, it turns out that my M59 doesn't do well on SUDT, so I went back to standard hydraulic oil.
Luck, rScotty

 

[jdonovan]

12 Gallons of hydro oil, what do you drain that into? A bath tub?

I though I had a fairly large oil drain pan at 12 quarts, but that is woefully shy of what I need for the M59.

 

[rScotty]

12 Gallons of hydro oil, what do you drain that into? A bath tub?

I though I had a fairly large oil drain pan at 12 quarts, but that is woefully shy of what I need for the M59.

Good Question! The bathtub made me chuckle. That sure is a lot of oil. If it's not contaminated with water, I don't know why people don't just filter the hydraulic oil and reuse it. It's not like it gets old does it? Unfortunately, my idea of using a vacuum to pump the hydraulic oil out of the filling port like one does on a ship diesel didn't work. Sigh....another good idea gone bad. So I was stuck with draining it.

There are two problems: what kind of drain pan, and what to use to store 12 gallons for disposal.

For the drain pan I had a black plastic one from NAPA. It holds several gallons and has wire bail plus a molded spout that works. Downside is it does require several trips back and forth to empty it. The initial 12 gallons of old oil went into empty Clorox bottles kept from treating the well that year. After that of course I had kept the containers that the hydraulic oil came in the time before. It does help to have a barn.
rScotty

 

[jdonovan]

That sure is a lot of oil. If it's not contaminated with water, I don't know why people don't just filter the hydraulic oil and reuse it.

My understanding is over time it does break down due to heat, and the anti-wear additives get 'used up' and you do need to replace it. Oh, and aren't we filtering it constantly while its in the machine? :laughing:

A quick search at northern tool shows many 12+ gallon drain pans. I guess looking at the local auto parts/tractor stores there just isn't that much call for their customers to need a huge drain pan.

As far as transport for recycle, the new Rotella containers are 2.5 Gal and I'm saving them for transporting oil to the county oil pick up site. I do expect to get some hassle from them when I show up with +/- 20 gallons. The county only takes oil from non-commercial users, so if you show up with a bunch they give you some questions.

Last time I showed up with oil from 2 bikes, the diesel truck, the BX22 + hydro, and it was about 12 gallons. They started to give me a hard time, but once I listed the vehicles, the guy nodded and pointed me to the recycle drums.

 

[ManAtArms]

Inner island.

For changing the hydro oil there are 3 plugs to drain. The main one on the pan (i think its something like a 22mm and the manual shows two of these, but everyone I know can only find one), and the other two are located at the bottom sides of the rear "axle housing", one on each side opposite each other. These are smaller like 13mm. If you didn't drain these 3 you prob wont get all of the oil out. Theres also a ton of oil in the 3 filters. I usually take off the shield to get at the two filters on the right side and watch the threaded filter mounting shaft on the left side filter, it will work itself loose over time and needs to be tightened periodically.

For the engine oil there are two drain plugs, one for each half of the oil pan that straddles the front axle.

Hope that helps .

Mark

 

[rScotty]

My understanding is over time it does break down due to heat, and the anti-wear additives get 'used up' and you do need to replace it. Oh, and aren't we filtering it constantly while its in the machine? :laughing:

Well, yes. Those are my questions too. I'm hoping to hear from someone like a PhD in petroleum engineering/chemistry.

How much heat makes how much of a change in hydraulic oil?I've no idea, but mine runs pretty cool compared to engine oil.
Does hydraulic oil even have additives? And if so, can additives be replaced for less than $10/gallon of oil?
Why do we throw old oil away? It bothers me.

As for filtering, I do know a bit about that. Yes, the filters catch the large particles, but nothing in the world separates out small particles better than just letting a mixture sit quietly for a long time. And that's easy to do with old oil.

The bothers me how little knowledge I have about oils. And what I do have is built more on rumor and opinion than on science. If this were a question about metallurgy, electronics, magnetics or water chemistry there's probably someone among us who is real knowledgeable. But for all the petroleum we use, there seems to be a lack of technical knowledge at the common user level.
Why?
rScotty