BX2200 HST oil foaming out dip stick hole

Heavyhook · Apr 12, 2012

I purchased a Kubota BX2200d with 279(if the meter is correct) hours? Machine looked to be in fairly good shape. Except the mower deck was covered with oil and dirt. Owner said the Oil had come from leaking hydro hoses that operate loader. Previous owner said that kubota dealer had recently replaced all loader hoses because of leaks and chafing on others.
During pre purchase inspection I had checked the rear dip stick above the pto that supposedly supplies HST transmission, power steering and hydro power to operate the loader. When I pulled the dip out( Engine running) of the hole hydro oil started bubbling out. It looked milky colored like the color of coffee with cream added. No burnt smell. Previous owner stated he had just changed the HST oil ( but filter trans filter was not changed) because of the leaking and replacing of hoses, and it was just air working its way out of the system.
After purchasing the machine and getting home I was doing a normal service on all the tractor systems and giving it a complete going over, but the hydro oil is still aerating and bubbling out the dip stick hole. If I had to guess I would think some oil had been used to top off the hydro sump that had been contaminated with water. I am going to change the filter and HST sump oil 2.7 gallons tomorrow.
I am concerned about excess foaming of the oil, even if the oil is contimated I just do'nt think it would cause this much areation! Is there any where air could be sucked into the system before the pumps? Is the spin on transmission filter under pressure like most spin on types? If so it should show a leak if the gasket was bad or the filter not seated properly?
I have a Kubota B7200 but its a standard transmission model? All the controls seem to work ok but I want to solve this foaming oil in the rear HST/PTO/hydro pump gear box before put it into service? I have ordered a Kubota owners and service manual from Colemans but It will not be here untill next week? Thanks for any input!

pdowling1 · Apr 12, 2012

It sounds like there is water in the transmission fluid. Was this machine stored out in the weather? I would change it with UDT from Central Tractor ( Cheap) and then change it again in maybe 10 hors with Kubota SUDT if the "Gravy" is cleared up. Meanwhile cross your fingers and hope the HST isn't damaged by the contamination. Change the filter both times. Just my opinion.

Deano · Apr 12, 2012

I would just go ahead and change the hydraulic oil. Don't forget, it all doesn't get changed. The lines etc hold some.
I have never opened mine while running though...
Good luck. Let us know what you find.

dex3361 · Apr 12, 2012

You can easily do a crackle test to see if it is water in the oil. Crackle Test I would also check the suction hose to see if it may be cracked or loose. I would make sure and check the suction screen (if there is one on this model BX there is on my BX1500). The other thing to check is to see if you might have the 3PH lift all the way up and it is bypassing. :thumbsup:

Heavyhook · Apr 12, 2012

Thanks for your input guys. I differently agree with the opinions that the oil needs changed most likely multiple times until it is clear on the dipstick. I believe I can unhook the loader and open up the lines then cycle the cylinders by hand to remove most of the contaminates from that area.
I don't have any idea where the suction is located. My Service and owners manuals should be here late Friday, they should help quite a bit!
I am not familiar with UTD oil. Locally in north central Texas I purchase oil in 5 gal buckets that calls its self Universal Tractor hydro/transmission oil. It is supposed to meet a "303" standard. Other brands show to be ASW 30 or ASW 60 weight oils. I have a 1970 JD 410 backhoe I use the cheap stuff in and seams to work fine. Although I never work it very hard when its used.

I will measure the amount that comes out when I drain the system. Does anyone think that maybe being over filled along with water contamination could be contributing to my symptoms.

When I purchased The tractor earlier this week It was parked under equipment awning next to a barn. I think the previous owner most likely grabbed a bucket of oil that had been left outside to top the system off after replacing the hoses he had trouble with.

I also own a Bad Boy 60" zero turn mower that uses the same principals as the HST drive. I requires a 5W50 motor oil. I will post a update after the oil and filter changes so you'll can see how that came out.

OrangeRidge · Apr 12, 2012

Kubota SUDT contains moisture sequestering agents that reduce
foaming aswell .Universal Tractor Oil is a 20W mono oil.

dex3361 · Apr 13, 2012

I think it would be a good idea to flush the system but the final hyd oil that I would recommend is the SUDTII. When I changed the fluid in my BX1500 I could tell a difference in the sound and how it ran. I suppose the previous oil was not a multi viscosity oil and was robbing a bit of power.:thumbsup:

gwdixon · Apr 13, 2012

I've used cheap hydraulic oil (Tractor Supply) in my BX2200 with poor results. Good oil makes it run quieter, smoother, and the hydraulics work quicker when cold. Cheap oil will also thin out much more when hot.

The tractor does not hold that much oil and the changes are not often enough for good oil to be a financial burden. Since you don't really know what is in your HST it would be wise to change it.

That said, cheap hydraulic oil would be a good flushing agent. A couple of changes ought to clear up any contamination problems. Maybe 5 hours or so between changes along with a filter each time.

The hydraulic hoses are a source of problems on the BX2200. I had to replace mine. Be glad that someone already did yours.

radioman · Apr 13, 2012

I dont check my HST oil when it running nor hot. I check mine when its off and cold. If it looks milky when cold, then you probably got water in it. If you checked oil when its cold and its really low, oil can foam up alot from sucking air and look like its overflowing.

Heavyhook · Apr 13, 2012

I have over 30 years experience operating and maintaining large hydraulic cranes, Up to 500 tons. Some of these cranes have hydraulic fluid tanks that hold up to 1500 gallons of oil. All their pumps and filters never run with any air going thru them. If air is going thru a pump, its causing damage is what we were always taught. We would sometimes would see a small amount of aeration but nothing serious. Maybe 1/4 thick floating on top the oil in the storage tank in which the oil could be 4 to 5 feet deep. Some of there pumps move over 300 GPM. One other point that might be of interest to others is we never changed the oil. The sump filters were changed @ 1000 hour intervals. Also the system designs are such that the oil is filtered just before it returns to the holding tank. Any small pieces of debris that came from control valves or pumps would be caught before the oil returned to the storage tanks and thereby insured clean oil to supply the pumps.
I agree that the oil should be checked when cold and not running. The reason for me removing the dip stick on the HST/PTO gear box with the engine running was that I could see oil leaking out past the seals built into the dip stick that seal it into place. When I pulled the stick with the engine running the oil was bubbling/foaming out of the dip stick hole. How ever much of the foaming is caused by contaminated fluid I wont know until I change the oil today.
I have a service and owners manual coming UPS today. I still need to find a parts book. Everything I am finding on-line has to be downloaded. I have a Satellite ISP that is slower than a snail. So thats really not good option.
DEX3361 recommended sudtII and sounds like the way to go. Does any one know where the SUDII is available and a brand name would be helpfully . I have some other small parts to pickup at my local Kubota dealer on Monday if they carry it.. I will use my cheap oil to make two flush and drain cycles and then do the final refill with SUDII. If its still foaming excessively after that, the system has to be sucking air in somewhere.
I well know that hydro pumps and drive motors are not cheap and the best oil you can use is a insurance policy that will protect these systems to get the maximum hours out of them.
Thanks again, its really nice to be able to bounce my thought off others with similar equipment!!!