# Need Hydro Tranny Bleeding Procedure In Frame



## orangputeh (Nov 24, 2016)

Does anyone here know a bleeding procedure for the hydrostatic transmission in frame?

We have a 928 with one seal partially out and the oil leaked out of the tranny. We were told by the dealer to push the seal back in and refill the reservoir but told us if that did not work then we would have to bring it in to have the system bled.

I have the Honda shop manual and it does show a procedure but it says you have to take engine out and practically take the whole thing apart.

why couldn't you put the blower up on the bucket with the tranny drain plug facing up and refill the reservoir until the oil came out of the plug? wouldn't that force the air out of the system or is there a specific procedure for that?

if anyone has done this before , please give me a step by step procedure to do this . Thank you.


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## orangputeh (Nov 24, 2016)

I ended up following the instructions in the Honda shop manual without taking it out as told .

I put the machine up on it's bucket. moved the reservoir so it was up and down. removed drain plug. 

took drive belt off so i could rotate the pulley wheel 30 revs in a counterclockwise direction. observed many bubbles so i thought i was on the right track. after i did not see any more bubbles put drain plug back on and added hydro oil to reservoir to proper level.

now, i'm not sure if this was right but i fired up machine , let it warm up , and it worked forward and backward. 

before doing this , one of the seals had been pushed out enough to leak the oil out and the tranny was not working right. it would go forward but not reverse.

so maybe i got lucky since it seems to be working right now. have not noticed any leaks but will keep a close eye on oil level in reservoir.


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## YSHSfan (Jun 25, 2014)

Glad that it worked out for you.
I have yet to deal with the hydro tranny fluid, so I could not provide any advise....


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## drmerdp (Feb 9, 2014)

I have a customer with a hs724 track machine. He’s looking for the Whole enchilada, serviced top to bottom including the hydro fluid.

What is everyone’s thoughts on using the same method that orangputeh used for bleeding after draining from the plug at the bottom of the transmission?

Figure I can always do the follow up procedure of strapping the machine in place while on a semi slick surface and engaging the drive to load up and further bleed the system. I’ve read that in the HSS manual, but not sure if it’s in the HS service manual. 

Thoughts?


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## orangputeh (Nov 24, 2016)

drmerdp said:


> I have a customer with a hs724 track machine. He’s looking for the Whole enchilada, serviced top to bottom including the hydro fluid.
> 
> What is everyone’s thoughts on using the same method that orangputeh used for bleeding after draining from the plug at the bottom of the transmission?
> 
> ...


i have read advice here on NOT changing the hydrostatic fluid. Honda says that the fluid is good for life. you may cause more problems. I had no choice because the fluid had all leaked out due to a pushed out tranny seal.

maybe other members will chime in with more info.


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## drmerdp (Feb 9, 2014)

Yeah, I’ve seen people say that it’s best to leave it alone unless a leak makes it nessesary to go down that road. This guys was pretty adamant about replacing the hydro fluid. 

Honestly, it doesn’t seem all that complicated to bleed. But maybe it is in fact best to leave it alone. No leaks no problems.


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