Fluid capacity issue

[Ellen B]

Hi everyone, I've got a Kubota L2501 with a hydraulic fluid capacity of 6.2 gallons. I just performed the 50 hour service, and changed out my hydraulic fluid as part of that. When refilling it I poured in roughly 5.5 gallons, and then ran the tractor for few minutes before topping it up, because I'm unsure if I need to circulate the fluid to get a correct reading on the sight glass. When I checked the sight glass, the fluid line was in there so I didn't add any more fluid.

Yesterday I removed the backhoe, attached the three point hitch, and did about an hour of work with a box blade. The tractor was operating just fine, but when I got off to take a break I noticed that the fluid was gone from the sight glass. I had purchased 7.5 gallons of fluid for the change out, and I added the remainder of that but there's still nothing in the sight glass. This morning I purchased another jug of fluid, and have already added about a gallon to the tractor, still without getting it to come up to the sight glass.

At this point, I've added about 8.5 gallons of fluid when the manual says I should've needed 6.2. I didn't spill any during the refill or backhoe disconnect, and I'm 100% positive that none leaked out while it was parked. I hadn't operated the three point hitch before yesterday (after the fluid change) in case it matters. Could there be that much fluid stuck in the backhoe (BH77, can't find fluid capacity specs though)? Or is there something else I'm missing? I'm hesitant to continue adding fluid until I figure out what is going on.

Thanks for your advice!

 

[Scook222]

If you have a front end loader on your tractor, lower it to the ground and lower the 3 point hitch. If you front end loader is raised several feet off the ground the fluid will not be in the sight glass. I have the same tractor as you and check mine with the bucket level on concrete and the 3 point hitch raised to be able to see the air bubble at the top of the sight glass. The bh77 shouldn’t affect the fluid level on the tractor unless it was just installed from the factory. With that much fluid in the tractor, you should be able to see it where you add the fluid. If there is no leaks, it is definitely over full.

 

[RickB]

Oil level is probably well above the sight glass. I hate them, they are a stupid idea.

 

[Ellen B]

The bucket and three point hitch were both lowered when I was filling or checking it. Are you saying I should be raising it?

When I did the service and filled the fluid up to the sight glass, the tractor was level. It hasn't been level since then as I've been adding more, but it's not that far off. I can try leveling it again tonight, I need to put the backhoe back on though as there's literally nowhere level on my property and I need the outriggers to get it set right.

The back of the sight glass is white, and the fluid is a light amber color (Kubota SUDT2). I haven't had any issues reading it before, and I'm seeing plain white with no hint of color whatsoever. Is there a way it could be over full if I'm not seeing any fluid at all?

 

[Scook222]

The tractor needs to be level when you check it. I check mine with the three point hitch up and the bucket flat but rolled forward on the ground so I can see the bubble at the top of the sight glass. I was suggesting raise the front end loader and 3 point hitch up high so it will take some of the fluid out of the reservoir to see the sight glass with the tractor level to see how much it’s over filled. If the tractor was full before you added the extra, it should be over full even if you can’t see it in the sight glass on a slope. Can you face the sight glass to the downhill side to see if it fills up the sight glass.

 

[ericm979]

The loader and backhoe cylinders's volume of oil does not change much when you extend vs retract them. There's oil on both sides of the piston. The only difference between extended and retracted is the volume that the rod takes up. The backhoe cylinders and lines are already full of oil. Putting the backhoe on does not take up a bunch of oil.

It's likely that the problem is that you're checking when the tractor is not level. Since the sight glass is at the back of the long transmission case, it would not have to be far off level to greatly change the reading at the sight glass.

Also some tractor fluid is clear. It can be very difficult to see the fluid in the glass when the line is above the glass. It looks like it's empty. They make oil dye to address this problem.

 

[Ellen B]

Alright, so I brought the tractor back to the house, reattached the backhoe, and used the outriggers to level it. Still nothing in the sight glass. Immediately after changing the fluid when doing the 50 hour service, I was able to clearly see the white background of the sight glass through the bubble in the hydraulic fluid, and that was with brand new oil, so I'm certain that I'm not mistaking a full sight glass for an empty one.

After that I tried positioning it in a bunch of different ways on a slope, and still got nothing in the sight glass.

Barring someone suggesting something else to try first, I guess I'm going to drain the fluid tomorrow morning and slowly put it back in. If I do that, should I be able to read the sight glass in real time as I'm filling it, or do I need to run the tractor to circulate the fluid?

And thanks for all your responses!

 

[oldnslo]

Ellen
Can you drain it slowly a little at a time while watching the site gauge? If yes this would save the trouble of drain and refill.

Other option can you stick a small rod or stiff wire in through the fill port to get some idea on the oil level in reference to the sight gauge. May not give exact level but could provide a reference on where the oil level is.

Not sure your tractor will accommodate the manual level check though.

 

[Ellen B]

I can definitely drain it slowly, hadn't thought of that since there's no fluid in the sight glass for me to watch, but it can't hurt and like you said may save me some hassle and mess.

And great tip on checking the level with a piece of wire. Based on the fill cap location and orientation I believe it'll be possible, unless there's something in the way of the wire on the inside of the tank. I'll try that later this morning after I get the goats moved into a new paddock, those goofballs have their priorities mixed up and don't seem to care about the tractor at all :confused3:

 

[Ellen B]

Ok, checked it with a wire and the fluid level is definitely above the sight glass. Could someone please let me know if I should be able to read the sight glass in real time as I'm draining or filling fluid, or if I need to run the tractor for a bit to circulate the fluid in order to get an accurate reading?

 

[Scook222]

It will almost be real time. It might settle alittle more once you get it full. Since you haven’t add a never used piece of equipment, you shouldn’t have to let it circulate once it’s full. It might settle alittle if you are draining it from the filter, instead of the drain plug, but no more than the filter will hold.

 

[Ellen B]

Ok great, thanks for the info. I'm going to use the drain plug.

 

[Ellen B]

Haha, well today I learned that you can't let the fluid out from the drain plug slowly. Anyway, after I made a mess I tried draining it from one of the filters, but only about a cup of fluid comes out before it slows to a drip, even with the filter removed completely, and I have to replace the filter and start/stop the engine to get another cup or so to come out. Is there any way to slowly drain a couple gallons of the fluid without having to go through the tedious process I just described?

Thanks!

 

[Scook222]

Those are the only two ways I can think of unless you have an oil extraction pump you might be able to put it in the fill port. I haven’t done the 50hr service on my L2501 but assumed it was like the M7040. On the M7040, the when you swap filters, it will gravity drain all the fluid from the tractor, about 15 gallons. I found out this the hard way the first time we serviced it.

 

[orezok]

Haha, well today I learned that you can't let the fluid out from the drain plug slowly. Anyway, after I made a mess I tried draining it from one of the filters, but only about a cup of fluid comes out before it slows to a drip, even with the filter removed completely, and I have to replace the filter and start/stop the engine to get another cup or so to come out. Is there any way to slowly drain a couple gallons of the fluid without having to go through the tedious process I just described?

Thanks!

You could try having someone partially cover the fill port with the vacuum side of a shop vac. You don’t want to create a vacuum in the tank, just offset the air entering through the tank vent. Then remove the plug and have them adjust the coverage until you get a slow flow from the drain plug.

 

[the old grind]

Somewhere in the service lore of the particular model may be something about having certain cylinders in certain positions when checking hydro level. I have to wonder if the sight glass is mostly for maintaining a minimum vs avoiding too much 'in tank'. The reservoir is more like a car/truck's cooling system thani t's lubricating system. Are there symptoms when going too far above sight-glass-level, or might this be like a 'best when used by' date on table salt?

In a hydraulic system it's only the reservoir that can ever be 'over-full', unlike an engine where high oil levels (common 'wet sump' setup we drive daily) can be stirred to foaming by crankshaft revolutions thrashing it. Machinery fluid levels are never fixed. Any & all fluids will expand when heated from 'room' to 'operating' temp. That's why we don't fill things 'to the cap', lest they spill out while running, and why there's typically an airspace at the top of a tank or reservoir. What I'm getting at is that if hydro isn't spewing from a breather or filler neck, is it really 'too full' as is for now and need to be drained lower?

I don't wish to steer the OP to some hocus-pocus approach, but sometimes 'the book' is so specific for the sake of 'the book'. Do we use only JD, NH, or Kubota-branded fluids, too? Hmmm ...

 

[Ellen B]

You could try having someone partially cover the fill port with the vacuum side of a shop vac. You don’t want to create a vacuum in the tank, just offset the air entering through the tank vent. Then remove the plug and have them adjust the coverage until you get a slow flow from the drain plug.

Perfect, thank you! It started raining so I'll give that a try tomorrow.

Somewhere in the service lore of the particular model may be something about having certain cylinders in certain positions when checking hydro level. I have to wonder if the sight glass is mostly for maintaining a minimum vs avoiding too much 'in tank'. The reservoir is more like a car/truck's cooling system thani t's lubricating system. Are there symptoms when going too far above sight-glass-level, or might this be like a 'best when used by' date on table salt?

In a hydraulic system it's only the reservoir that can ever be 'over-full', unlike an engine where high oil levels (common 'wet sump' setup we drive daily) can be stirred to foaming by crankshaft revolutions thrashing it. Machinery fluid levels are never fixed. Any & all fluids will expand when heated from 'room' to 'operating' temp. That's why we don't fill things 'to the cap', lest they spill out while running, and why there's typically an airspace at the top of a tank or reservoir. What I'm getting at is that if hydro isn't spewing from a breather or filler neck, is it really 'too full' as is for now and need to be drained lower?

I don't wish to steer the OP to some hocus-pocus approach, but sometimes 'the book' is so specific for the sake of 'the book'. Do we use only JD, NH, or Kubota-branded fluids, too? Hmmm ...

I don't know enough about the topic to have my own opinion about moderate overfilling past spec, but I did read some other folks saying something along the same lines and that logic makes sense to me at least. In this case I'm not a little over though, I'm (presumably) 30% over.

I drove the tractor back to the shed yesterday to work on it, and this morning there was fluid on the ground under it for the first time. It's parked on plastic so there's no soak-in loss, and the amount that's there makes me think that it was leaking during operation but not overnight, so that what I'm seeing is just the residual drop off the tractor. Both filters definitely leaked, and while I didn't give it a thorough look over yet I'd guess that it was coming out elsewhere as well. As it never leaked before, including after I serviced it, this is proof enough for me that I need to remedy the situation before putting the tractor back into use.

But since there's no significant anecdotal evidence online about damage from moderate overfilling, I do suspect you're right about that.

 

[Fallon]

John Deere Lubricants - John Deere #MT3668 Hydraulic Oil Dye (from any JD dealer) is your friend. I hated that sight glass & clear SUDT2 on my L3200. Half the jar of dye in the sump makes it look like ATF. That way you can see if the oil level is above or below the glass.

You also get erratic readings from not being level or having the impliments raised.

The shop vac trick to not let oil out of the pan works great for changing filters without dumping oil. I'd imagine you could use it to not make a mess then turn off the vac to drain some oil out, if needed.

 

[Ellen B]

John Deere Lubricants - John Deere #MT3668 Hydraulic Oil Dye (from any JD dealer) is your friend. I hated that sight glass & clear SUDT2 on my L3200. Half the jar of dye in the sump makes it look like ATF. That way you can see if the oil level is above or below the glass.

That's perfect, thanks! The nearby dealer doesn't have any in stock but they ordered it for me. In the meantime, I just drained out two gallons of fluid and am calling it good til the dye gets here. Thanks again for your help everyone!

 

[Fallon]

That's perfect, thanks! The nearby dealer doesn't have any in stock but they ordered it for me. In the meantime, I just drained out two gallons of fluid and am calling it good til the dye gets here. Thanks again for your help everyone!

I only used half the jar on my L3200 & was happy with the results. My new L4060 has a dipstick (yay!), but I can still barely see thad dam clear fluid on the stick. I went to use the 2nd half of the jar on the L4060 & it was all dried out. Not sure if I didnt get it sealed well or what. Still thinking about getting another jar.

Just let any mechanic or future buyer of your machine/impliments know. Otherwise they might wig out that you put ATF in instead of the proper fluid.