Hydraulic/trans flush

[alvanko]

I am thinking about flushing out the trans/hydraulic system. If I drain and refill with diesel/kerosene , start and run til warm , then drain , do you think I will do any damage to the hydraulic pump ? I wouldn't put it under load , just flush . Drain and refill with proper oil. Would the residual diesel/kerosene contaminate the fresh oil? Thoughts or ideas ? I have to pull the bottom trans cover off anyway due to a 4x4 lever problem.

 

[KiotiJohn]

I'm certainly no expert, but I wouldn't want any amount of diesel fuel to be in my hydro system.
As far as I know, the better way to do it is simply to use new hydro fluid, flush it and replace it with same.
Maybe someone with more hydraulic experience has a better idea. John

 

[DFW]

The manual for my tractor says to drain and fill with diesel and run to flush all the gunk out in EVERYTHING, including the engine at 50hrs. Then refill with fresh oil/hyd fluid as appropriate. What does your manual say about flushing?

As a side question, what do you TBN'ers do with all of the diesel after flushing? At $2.39/gal and I need about 15g, that's a lot of wasted fuel and money...

 

[Soundguy]

Well.. the remnant diesel will thin the oil a tad.. but that would not be my major concern.. the concern would be for the hydro pump... Diesel oil has a much lower vapor pressure than hydro fluid... that means cavitation can happen very very easily... Cavitation can destroy a hyd pump in minutes....

That said.. do whatever your manual and warranty say is ok.

Soundguy

 

[KiotiJohn]

</font><font color="blue" class="small">( As a side question, what do you TBN'ers do with all of the diesel after flushing? At $2.39/gal and I need about 15g, that's a lot of wasted fuel and money... )</font>
IF I were to do this, I would run the diesel through my Mr. Funnel back into the tractor and burn it up. There shouldn't be enough of anything that would not be filtered either through the funnel or the tractor's filter to do any harm. John

 

[alvanko]

Thanks for the replies . The tractor is an old 70's Kubota grey market . I doubt the manuel says anything about flushing.Long out of warranty ! /forums/images/graemlins/laugh.gif
I have to agree that you could probably strain and use the fuel aftyer flush so as not to waste the diesel fuel .
As far as vapor pressure (?) , what do you think of maybe using ATF as a flush ? It is suppose to have a high detergent level.

 

[Soundguy]

Though I'm no expert.. I imagine ATF would be way easier on the hyd pump than diesel... atf is basically a fluid power media... cheap too. If I only had the option of flushing the transdraulic system with diesel or atf.. my choice would be the atf... ad you know it is safe on yellow metal, aluminum, plastic and all major seals used since the 60's, and does have lubricating properties.

Soundguy

 

[JeffRey30747]

I think that I would just buy a 5 gallon bucket of the cheapest transhydraulic fluid that I could find and flush the system with that. Since it is a 70's Kubota grey, that might be what I opted to run in it too. I'm running generic JD303 equivalent in my Yanmar that I bought at Sam's club for about $17.50 a bucket.

Jeff

 

[DFW]

Thanks John, that's what I was thinking, just needed a little reassurance that it's doable.

 

[KiotiJohn]

</font><font color="blue" class="small">( As far as vapor pressure (?) , what do you think of maybe using ATF as a flush ? It is suppose to have a high detergent level. )</font>
If my memory serves, ATF is a 10 WT oil and shouldn't be a problem to use for flushing the system. Go to an auto parts store and buy the cheapest they have in large container to save money. I would make sure to drain all the plugs until absolutely nothing came out. Good to the last drop! John