Looking for recommendations on HST fluid for my Kioti DK40 SE HST tractor

[IXLR8]

I have a DK40 SE HST and in the cold weather, less than 20dF, the HST will continue to drive for a few seconds after I take my foot off the pedal. The colder it gets, the worse the problem is, that is the longer it will continue to drive after I take my foot off the pedal. If I am going from forward to reverse, pressing on the reverse pedal does no good as the pedal won't move for those few seconds. My dealer replaced the entire HST unit under warranty, tractor still does the same thing. The dealer puts Navigard hydraulic for tractor in the HST units. I haven't been able to find much in the way of specs for this fluid, but from a MSDS I found, it looks like it is a Chevron product. I asked him about putting in a synthetic HST fluid, but he said there was no need to. His only comment regarding HST fluids was to never use the Traveller fluids from TSC. Although he wouldn't say why except he has seen nothing but issues on tractors that have used it. I am considering either the Amsoil synthetic HST fluid or the Kubota SUDT2. I was wondering if anybody had any idea if putting a synthetic oil in my HST would help with my issue? I am ready to give it a try, but since I need about 12 gallons, it is an expensive experiment. I am about ready to buy a quart of each, leave them out in the cold and see how each one pours. The pour point on the SUDT2 is listed at -42dF, the Amsoil is -50dF, not really that much of a difference. I have no idea about viscosity/pour points on the Navigard. But I am thinking that Navigard is a standard dino oil and the pour points will be a good deal higher, aggravating this situation.
Thank you,

 

[IH3444]

I use the Amsoil, but as most don't like their marketing. Plus it's a wait to get it shipped. Either one will be good, if the Kubota SUDT2 is easier to get, then it will do fine.

 

[IXLR8]

I have been happy with Amsoil products in the past, although they are getting a bit expensive.

I finally found full specs on the SUDT2.
*Amsoil* -SUDT2-
Viscosity @ +100dC *10.1* -8.1-
Viscosity @ +40dC *55.4* -37-
Viscosity @ - 40dC *18797* -16000-
Pour point *-50dC* --42dC-
Cost for 12 gallons *$490* -$250- price does not include tax and/or shipping.

Since I believe cold flow is my issue, I think it is time to visit my local Kubota dealer and see what his pricing is like.

 

[Redlands Okie]

Perhaps call some other Kioti dealers and see if any have suggestions of a different problem ? Before you spend all that money.

I do know some tractors have a adjustment on response time to changes of HST petal. Not sure if its all electronics or has some actual mechanical functions in some aspects.

 

[Langanobob]

It seems to me that the dealer should provide the synthetic fluid if the tractor is still under warranty. The cost of the fluid isn’t much compared to the cost of the complete drive unit they already replaced. I have enough trouble with the lag between my brain and my feet and can’t imagine trying to operate with a further lag in the pedals. Definitely a possible safety issue and something the dealer needs to handle.

I agree with Redlands Okie above about checking with other dealers. The drive systems are all very similar and you could also check with other brands.

My guess is that the synthetic fluid will solve your problem but it’s just a guess. Do you have another machine you can use the old fluid in? That would ease some of the pain of buying the expensive new fluid.

Good luck with it.

 

[IXLR8]

Just for a data point, I made a viscosity cup to get an idea on how thick the different fluids were. I checked the Traveller Premium from TSC, the Navigard that my dealer put in my tractor and the Kubota SUDT2, it was 4dF this morning when I ran the test.

Fluid- Time to empty
TSC- 1' 55"
Navigard- 1' 25"
SUDT2- 0' 48"

I wish the Amsoil had arrived in time to do this test at the same time. It is obvious that the SUDT2 flows better than the other 2 at this temperature.
It may all be a mute point. The other day, at -4dF, I started my tractor and after about 20 seconds of running there was a horrible squealing coming from the engine area, I shut it down as quick as I could. I waited about 5 minutes and started the engine again. After about 10 seconds the squealing came back louder than before and I immediately shut the engine off. I waited about 2 hrs, temps warmed up to +5dF, and started the engine again. No squealing this time, but the next day I went to use the tractor and it just felt like the brakes were on and dragging, but they were not. And the engine speed vs tractor speed based on the HST pedal position was not the same. I think the squealing may have been the pump being starved of oil and is now shot. Call going into dealer today.

 

[GMIslander]

I use this in my 2012 DK45 SE HST.



I put this in at my 400 hour service. It works perfect for me. Some tractor owners complain of HST whine with different fluids but this is fine by my standards even in cold weather. I don't think these model tractors are noted for having much of a whine.

If you do change it save yourself some $$ and just buy two cans, (10 gal). The specs say 11 gallons but you will not get a full 10 in it.
I have over 500 hrs. now and the fluid is as clear now as when new.

 

[crazyal]

While I think you will notice a difference with synthetic oil I don't think it would of solved your problem. Once you start using your tractor the fluid should warm up so any problem based on it being cold should only be temporary. While I know it sucks that your tractor is broken again hopefully this time they can solve the problem.

 

[AWSubie]

I use the TSC Traveller Premium and have not had any issues. However, the coldest I have operated the tractor is 25'F. When I operate at low temps I let the engine/tranny warm up for between 5-10 minutes before I start running around.

 

[IXLR8]

I use the TSC Traveller Premium and have not had any issues. However, the coldest I have operated the tractor is 25'F. When I operate at low temps I let the engine/tranny warm up for between 5-10 minutes before I start running around.

I let the engine warm up for 5-10 min's as well when it is cold out. But when it is 0, or below, it takes almost an hour of using the tractor before the tranny fluid warms up enough to operate properly. Warming the engine doesn't seem to do much for warming the tranny fluids.
I talked with the service manager yesterday, he reiterated that synthetic fluids were not necessary and he had me talk to his Kioti mechanic about the noise and issues. The mechanic said it sounds like the hydraulic pump caveated, ran without fluid and most likely the pump needs to be replaced. He also said that he recommends and runs synthetic fluids in his Kioti and suggests I do, but that is not the official position from Kioti, or the dealership.