BX2200 HST fluid return flow and vent locations and questions

[RichInTN]

On the BX2200 HST, does the oil return through the point marked in blue in the attached image? And is the point marked in red an open vent at the top of the HST? If not where does the fluid return from? The charge relief valve (items 15/16 in the attached image) appears to flow the excess pressure in to the front HST housing if I am seeing the diagram correctly. That oil would then need to return, and the only passage I see is the one circled in blue in the attached image.

I am trying to determine why oil would be coming out of the point circled in red. A slow steady drip starts up a couple of minutes after the tractor is started. Seems like an understanding of the flow of oil in the HST was a good thing before removing the HST, particularly if it might be something as simple as the Charge Relief valve having an issue or the return path being restricted. Certainly hoping it is not one of the motors leaking. The 3pt Hitch, Steering and even the HST seem to be operating normally, no loss of power or unusual noises. Just the steady drip from the top vent of the HST while running.

Any information is appreciated, Thanks!

 

[whitetiger]

I do not believe that there is supposed to be an opening where your red circle is. If it's leaking, it must be cracked or a faulty casting.

 

[RichInTN]

I do not believe that there is supposed to be an opening where your red circle is. If it's leaking, it must be cracked or a faulty casting.

I am fairly certain there is an opening that is there by design. Now it may should have a freeze plug or threaded plug in it, but the opening is definitely in the casting and not a crack. It is the top of the front HST housing, not the back section with the relief valves in it.
I have circled in red the point where the oil is coming from in this picture I found on the internet. It is the best picture I could find.

Thanks

 

[whitetiger]

True, the opening is cast in the housing, but on this application, it is not drilled thru. This casting is used in other applications and is milled open for a filter.

 

[RichInTN]

True, the opening is cast in the housing, but on this application, it is not drilled thru. This casting is used in other applications and is milled open for a filter.

Thanks,

I stand corrected. Not the news I wanted to hear. Guess it is time to pull it a part and take a closer look. I sure was trying to avoid that.

Richard

 

[Dave_eng]

Thanks,

I stand corrected. Not the news I wanted to hear. Guess it is time to pull it a part and take a closer look. I sure was trying to avoid that.

Richard

The photo of the transmission you found on line and which you say looks like yours seems to have a plastic plug in the leaking hole.

Before tearing into yours I would consider a thorough de-greasing and then decide if an epoxy could be used to seal it up or, if there is a hole, then consider an expanding rubber plug.

Dave

 

[RichInTN]

I tried plugging the unused filter port. This moved the leak to the top of the gasket between the two parts of the HST. It appears either the gasket has failed or the casing has warped. Either way I have to pull the HST to check it out. The next question is, if the gasket failed why? Is there a blockage in the return port at the top of the HST causing a pressure build up? Was the gasket defective and failed? Did the HST overheat and warp (or is that even possible?)? or ???

 

[martinlaurentide]

I tried plugging the unused filter port. This moved the leak to the top of the gasket between the two parts of the HST. It appears either the gasket has failed or the casing has warped. Either way I have to pull the HST to check it out. The next question is, if the gasket failed why? Is there a blockage in the return port at the top of the HST causing a pressure build up? Was the gasket defective and failed? Did the HST overheat and warp (or is that even possible?)? or ???

Just wondering how this turned out.