R520S leaking hydrolic oil

[chevtoy]

Hello I am new to this forum and was hoping to get some help for my loader.

I have a R520S loader that is leaking oil (motor oil for hydraulic oil on this particular Kubota)from the transmission filter. I purchased a new filter and put it on. Once i took the old one apart I had a feeling that was not the problem as it was just a simple air filter. After a day of use oil is once again pouring from the air filter on top of the transmission.

I am guessing that there is possibly another air vent that is stopped up and causing a pressure build up, but cannot locate one.
Once again any help would be greatly appreciated.

 

[fast*st]

First guesses would be overfull or another vent causing some issues. Is the fluid level and type correct?

 

[chevtoy]

yes it is the correct fluid 10w-30 motor oil for hydraulic oil on this model which is weird but correct.
yes it is at the correct level on the site glass.

 

[Bulldog]

Does it leak all the time or just when it's at operating temp?

The filter you have in the picture I assume is the one leaking, did you check the fitting it screws into and make sure it was open. I have seen cases where these type breathers would leak oil out but were clogged enough so that they couldn't vent propperly.

 

[chevtoy]

It is only leaking at operating temperature.
The photo is the filter. I will unscrew it back out tomorrow and make sure where it screws in is not stopped up.
I do know that when the old filter was off and the machine was cold nothing leaked out. Only after using the loader for while did it start leaking.
On this loader the transmission fluid and fluid for all the rams are from the same tank which as stated above is motor oil.

 

[Bulldog]

Does it leak alot of oil or is it just a few drops which turns into a big mess? The reason I ask is on my tractor when I do lots of loader work the vent will have enough oil vapor come out to make a mess. It doesn't really leak oil out but more like moist air I guess you would say. It only does this during quite a bit of heavy loader work. Normal operation it doesn't leak anything out.

 

[chevtoy]

My wife runs our nursery business and I usually only hear about things when there is a problem.
So finally I am told last week that in about 3 months the loader has gone thru 10 gallons of oil.
Luckily it does not look like the pump was hurt.
What kills me is it took 10 gallons before she thought there might be a problem.

 

[Bulldog]

Well, that answers that. 10 gallons is a pretty good leak. Maybe you will get lucky and it's just the vent stopped up.

 

[chevtoy]

Thanks for the input.
I have spoken to several dealers and it appears the transmission seals might be blown out and allowing fluid in to transmission when the rams are operating which is causing the transmission to puck oil.
Now just have to load it on trailer and get the check book out, I am sure it is going to hurt.

 

[Bulldog]

I've been thinking about this in the wrong mind set. I was thinking about it like a tractor instead of a wheel loader. If these are like standard wheel loaders the transmission and hydraulics are two separate systems. You said earlier that the trans fluid was at the proper level. I don't understand how working the lift arms will change the fluid level in the tranny. Does this machine have a hyd tank or is the transmission a reservoir like a tractor?

 

[chevtoy]

On this model it uses the same res tank for the transmission and rams. So according to the dealer he says he has seen this before when the seals go out on the transmission it will force oil into it and out the breather.
This is what he thinks it is and will not know until they can diagnosis it.

I did have something similar on a truck one time when the seal went out between the transmission and transfer case and the transmission was continuously overfilling the transfer case.

 

[bosshogg]

This may not help but you said you changed the hydraulic filter. Could they gasket from the original filter stayed in and you placed the new filter up against it? Probably too simple but thought I would throw it out there.

 

[chevtoy]

I wish it was that easy also. The filter I changed was the air filter on top of the transmission. This was the filter that was leaking in the first place before it was replaced.
The loader will leak after being used from this air filter/breather until the level gets below the filter level and then quits. The dealer is right in that when the loader is being used it is somehow pumping fluid into the transmission and overfilling it. This causes the entire hydraulic system to become low as it is the same fluid for the whole loader.

 

[kentnsry]

Chevtoy-
What was the outcome? I have 2004 R520S with the same problem- After using the machine to move snow we parked it in the warm garage and the next morning came back to find at least a gallon (maybe more) of the hydraulic fluid all over. Seems to be leaking from the breather valve off the transfer case.

What's strange is we had this exact same problem this time last yr. We couldn't figure it out ourselves so we added more fluid and kept an eye on it. All spring and summer we never leaked a drop of fluid. Now all of a sudden that it's cold and snowing we have the same leaky breather valve again. Can't figure it out.

Our local dealer also mentioned the seals in the drive pump may be bad and filling the transfer case with fluid, causing it to overfill and come out the breather valve. But why wouldn't it continue to leak during the warmer months?? We're not talking a small amount. There was over a gallon on the floor just from overnight.

Thanks!

 

[nurserygrower]

Kentnsry -
Wondering if you have solved your problem? I have an R420 that is doing similar to what you described, except the machine had not been running much prior to the leak. It was in a cold barn during very cold weather that the leak was discovered.

I also noticed last fall that the oil level in the sight glass always seemed low, even though we were filling it. However, it was not leaking any oil at that time. The leak started this winter, and I noticed it after it had been sitting for awhile in very cold weather. There was a large puddle underneath it at that time.

Hoping that it was a seal that leaked in the bitter cold weather, I waited until the weather warmed a bit this March and topped off the machine and ran it for about 2 minutes. Parked it and no leak for a day. Then it leaked all over again the next day (without running it at all) and the oil level in the sight glass dropped out of sight.

At this point, it appears that the breather is leaking. I plan to fill it again, run it, and see what happens now that the weather is warmer (50-60 degrees).

Anybody have advice?

Thank you!

 

[Bulldog]

Make sure the breather is clean so it can't build up pressure.

 

[lextech]

any info on the fix for this.. I have a R520s doing the exact same thing.. Its hit or miss.. sometimes it just leaks a little from the breather.. other times its a steady stream.. Thanks in advance

 

[Special_K_Side]

I also have this exact same issue. Any response on the fix? Oh, and thanks for this wonderful forum folks!

any info on the fix for this.. I have a R520s doing the exact same thing.. Its hit or miss.. sometimes it just leaks a little from the breather.. other times its a steady stream.. Thanks in advance

 

[ad1]

I also have this exact same issue. Any response on the fix? Oh, and thanks for this wonderful forum folks!

any info on the fix for this.. I have a R520s doing the exact same thing.. Its hit or miss.. sometimes it just leaks a little from the breather.. other times its a steady stream.. Thanks in advance

I have exactly same problem on my r520s. Any info to fix please?
Thanks

 

[ad1]

Hello

I have exactly the same problem on m'y r520s. Oil blow out on breather
Any info to fix please?

Thank