B7100 Water (?) in Hydraulic Fluid

ojaikubota

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B7100
Sep 1, 2015
16
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1
Ojai, CA
I have an early 1980s B7100 with a manual gear drive. I use it only for bush hogging a 2 acre horse pasture 2-3 times a year and maybe 2-3 times a year dragging it. Every couple of years the hydraulic lift stops working - I check the hydraulic oil on the dipstick (photo) and its like (almond) milk. I've drained it now 4 times over the years and the oil filter screen (there's only one) is completely clogged with a white creamy oily residue. Clean the filter, new oil and the lift is fine again. The filler cap and the dipstick are sealed - can't see how these are letting rain in. How can water be getting into my transmission hydraulic oil? The engine radiator uses some water - is it possible that the coolant is getting into the hydraulic oil? I'm using the best Kubota Hydraulic Oil Super UDT - but would be interested in a cheaper alternative given this situation. I have a FEL and don't have water in that. I'm hoping there's an obvious simple answer to this. Thanks!
 

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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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Shifter seal / boot

UDT or Mystik JT-5
There is no need or advantage for SUDT2 in that tractor.
 

85Hokie

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I do not know of a way that water can backtrack to the hydraulic oil - I am with everyone else, the boots are dry rotted or somehow you have a huge condensation problem - and I do not think that is the problem!

If outside - tarp it well!

I too agree with NIW - no need to throw S-UDT2 in that machine, that oil is fantastic - but there will be little gain in that machine, only gain will be the loss in the pocket.
 

ojaikubota

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B7100
Sep 1, 2015
16
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1
Ojai, CA
Thanks - I store it outside and did replace the shifter boot last year. Maybe there was already water in there. I will cover up the shifter and filler going forward.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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See this post on a method to flush the transmission. Use a sacrificial 5 gallon bucket of cheap fluid


use fluid like this, good enough for a geared tractor

I bought something like this and use it to cover the area where the shifters are. Flip it upside down and flip the seat forward and place tub over the seat and steering wheel. And I bought a garage in a box and use the frame as a storage place and keep replacing the plastic tarps which don’t last very long in Texas sun.

 

D2Cat

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I have a piece of equipment that has been out in the open it's entire life. It has a 4 sped gearbox. I keep the shifter boot in excellent condition, but I also cover the entire shifting lever with a feed sack. I roll the edges of the sack to the inside, put it over the shifter and use bungee to hold it there.
 
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ojaikubota

New member

Equipment
B7100
Sep 1, 2015
16
0
1
Ojai, CA
Thanks everyone for your answers. I'm blaming the old shifter boot. @wolfman - are these the 4 drains you mention? The red bolt on the left side doesn't have a screen. My parts list shows only one screen on the rights ide but I've seen posts with 2 screens.
 

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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,161
6,329
113
Sandpoint, ID
Yes that's all the drain on the rear.
And yes the DT has just the one screen filter, where the HST has 2 screen filters.
 

Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
5,354
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Austin, Texas