Hytrans question

[Ken (48 Cub)]

OK Paul and the rest of you CC experts, someone please explain the flow of fluid through this pump. I am trying to understand it a little better, a flaw in my character I guess. Does a manual exist for this thing? What would be the best way to REALLY clean it out good?

Here is a picture of where I'm at so far:



I am trying to fix a very leaky pressure release valve once and for all. Does anyone have a used one that they would part with? Can these things be rebuilt? I don't want to mess it up trying to get it apart.

It looks like this:



It's almost mowing season here in Kentucky Thanks

[R Bedell]

Ken:

The flow of fluid through the Sundstrand starts in the Sump. It is drawn into the Charge Pump via the filter. The Charge pump creates a pressure (ie: 200#) and is then sent to both Check Valves and to the Variable Pump. Depending on the movement of the Swash Plate, this Variable pump will send High Pressure Fluid to the Fixed Motor to turn the output shaft (and on to the rear wheels via the transmission). The Varibale Pump can direct fluid one of two ways, thus you get your Forward & Reverse.

Sauer-Danfoss does have manuals available. You will have to order the manuals from them. You will need manuals: BLN-9646 Rev E, BLN-9659 Rev C. and BLN-10006 Rev B.

The Check Valves are NOT repairable. You can clean them and check for free movement and that is it. If you need a Check Valve(s), you will need Part Number #SU-9500085

You may get a bunch of different answers on this, but from view, there really isn't any procedure to dump something into the Hydro to clean it up, at least that I am aware of. Removing the rear Transmission cover, draining all the oil, cleaning up the Transmission as best you can, blow out any debris from the cleaning process, then replace the cover (new gasket too), install new HyTran & a new Hydro filter should be adequate. If you have additional concerns, after a few hours, you could change out the Hydro Filter again.

I sent you an Email with a Flow Chart, since I haven't figured out on how to post pictures here yet.

[Ken (48 Cub)]

Thanks R, I did receive your email. Is there some kind of cleaning fluid to run in it for a while like they run kerosene in the big cubs?

I was afraid that the valves could not be rebuilt They want $100 for a new one.

[R Bedell]

Ken:

NOT that I am aware of. The thing that I would be concerned about is the lack of proper lubricant to the Charge Pump. After all, that spins at Engine RPM's. So, I would think it would be safer to simply install the HyTran and change out the Hydro Filter a couple of times, to clean up any residue or gunk. The filter is cheaper to replace than any of the internal parts to the Hydro.

[Paul B]

Ken
The Cub Cadet chassis service manuals for models that have hydrostatic transmissions have some pretty good basic maintenance procedures for the hydro's, probably not as indepth as manuals from Sauer-Danfoss, but will probably cover what you need. As R said, not any magic stuff to pour in it to clean it out, but there probably is not much in the hydro to clean out. If it had Hy-Tran in it , most of the junk is going to be in the rear end case. You stand a greater chance of getting dirt in the hydro with the check valves and other plugs out of it than you do having the junk you see in the rear end collecting inside the hydro. Change the filter, and be sure you use a filter made for hydraulic systems and not an oil filter that fits, new Hy-tran and run it for awhile and then change the filter again.