Mixing Super UDT and UDT

[medfieldtractor]

I have an HST B7500, and plan to replace the UDT with Super UDT when I do the 50 hour service (as recommended in my owner's manual). It's my understanding that HST B7500's come from the factory with UDT in them (not Super UDT), a fact that is not made clear in my owner's manual nor in any other information I have been able to get from Kubota. I know that there are four drain plugs to remove under the transmission and undercarriage area (and two filters, one on each side of the tractor - - and a UDT strainer adjacent to one of the two filters) and that these drains will allow most all of the UDT to drain from the system. However, unless I open up the hydraulic lines on the FEL and drain the UDT from them and from the FEL cylinders when I make this fluid change, that UDT will mix back into the system (mixing into the new Super UDT) as I use the FEL. I am under the impression that UDT and Super UDT are compatible and that some mixing of the two will not be a problem. Does anyone on this very knowledgable and helpful forum have any information and/or experience on this issue?

 

[Bird]

<font color=blue>I am under the impression that UDT and Super UDT are compatible and that some mixing of the two will not be a problem.</font color=blue>

That's right.


Bird

 

[ronjhall]

Peter
According to numerous conversations with <font color=orange>Kubota</font color=orange>. All Hydrostatic tractors are shipped with Super UDT.

 

[snowman]

My B7500HST only has one hyrdraulic filter - you sure yours
has two?

 

[Pks]

wish my b2400 had two filters.

 

[medfieldtractor]

My B7500 HST does have two filters, one for hydraulic fluid and the other for the transmission (in addition to those two filters, it also has a UDT strainer, an oil filter, and a fuel filter). They are located on each side of the tractor near the back, in behind the rear wheels. As I understand it, the same fluid is used for hydraulics and for the transmission, and the fluid changing process is described in the owner's manual as one operation. For that reason, and because there is only one dip stick to check the level of the UDT (or Super UDT) I assumed that it is one unified system, and all UDT (except the separate reservoir of UDT used for the front wheel drive) was eventually pumped through both filters. Perhaps the systems are discreet - but then why only one dipstick?