Oil & Fuel HST oil level

   / HST oil level #1  

don white

Silver Member
Joined
Sep 29, 2011
Messages
140
Location
South eastern Pa.
Tractor
kubota B26
So I have an observation that I am wondering if anyone else has noticed. I have a B26 and when I check the HST oil level before start up it is never on the dip stick. When I put the dip stick back in and take it out again then the oil registers on the dip stick. It is weird. I guess I am wondering about a vent problem? I have no other problems with the system.
 
   / HST oil level #2  
I was always taught to "double dip" all dip sticks to get an accurate reading. Some equipment will vaccum off the dip stick tube during operation and wont refill until dip stick is pulld out. I have seen this on other equipment, both engine oil and hydraulic oil dip sticks. I think your system is fine.
 
   / HST oil level #3  
I always double dip for all my equipment (tractors, gen, cars, etc). Wish Kubota didn't use yellow as it is hard to see the level.
 
   / HST oil level #4  
I marked mine with a sharpie it helped.
 
   / HST oil level #5  
I'm a double dipper, hot or cold.
 
   / HST oil level #6  
I always double dip for all my equipment (tractors, gen, cars, etc). Wish Kubota didn't use yellow as it is hard to see the level.

I marked mine with a sharpie it helped.

I lay the dip stick on a paper towel and observe the "damp" level relative to the full level.


Steve
 
   / HST oil level #7  
I always double dip for all my equipment (tractors, gen, cars, etc). Wish Kubota didn't use yellow as it is hard to see the level.

I added John Deere "hydraulic dye" to my Kubota HST system;makes it much easier to see.Something like $4.99/ea.;I added two.Note: it didn't turn the tractor to green and yellow!
 
   / HST oil level #8  
"HYDRAULIC DYE"....what a great idea......Gotta' get me some.
 
   / HST oil level
  • Thread Starter
#9  
I like the hydraulic dye idea. Do yuns think we can trust that guy from NY. I am gonna be pissed if my tractor turns green. :)
I also like the paper towel system.
Never any trouble seeing the engine oil.

I guess I am not explaining what is happening very well or it does not happen to anyone else. There is NO oil on the dip stick the first time I pull it out. When I put it back in and pull out then the level is registered on the stick. I am thinking some kind of vacuum is holding the oil away from the stick????. Or I am just wacko. The 70s were a long decade.
 
   / HST oil level #10  
Don White.....I know what you mean. My B2650HSDC is the same..The 1st pull of the dip stik is dry but when I re-insert it registers between the full/add lines.
 
   / HST oil level #11  
Think of it this way. Place a small dixie cup upside down into a sink full of water. The airgets trapped in the cup and the water wont let air out. You can push the cup all the way into the water and the air pocket stays in cup. Now poke a hole in the bottom of cup that is at top of water level. The air can get out and the water will rush in cup to rest of water level out side the cup.

Now think of the cup as the dip stick tube. Think of the sink full of water as the hydraulic reservoir. Plenty of ventilation as no cover over sink to seal it in. When you poked a hole in the cup, you allowed a path for the air to get out of the cup. When you remove the dipstick, you give the air a path to get out. Then the fluid level can be checked when you re dip.

There is likely no vent problem what so ever with your tractor.

The reason I think some equipment will do it and others don't, is due to how well the seal is on the dip stick. I am sure there also might be other reasons as well.

The reason the fluid level goes below the dip stick can be due to either hill operation or usinghydraulic functions that take fluid from resivior and to implement, example, loader.
 
   / HST oil level
  • Thread Starter
#12  
Kanook
Thanks it is nice to know I am not wacko. I still think there should be a crank case vent somewhere.
 
   / HST oil level
  • Thread Starter
#13  
Namesray
Yea I get what you are saying and it makes sense. The case gets pressurized and compresses the oil so the level appears lower until you pull the stick. Again it seems like there should be a case vent.
 
   / HST oil level #14  
Namesray
The case gets pressurized and compresses the oil so the level appears lower until you pull the stick. Again it seems like there should be a case vent.

The oil is essentially in-compressible. Using a compressible fluid would defeat the main benefit of a hydraulic system.

I think what Namesray suggested (makes sense to me) is that the dipstick tube is a pocket that air can get trapped in when the tractor is tilted during operation, or the fluid level goes down slightly and back up during use of an implement. The only way that bubble can get out is when you pull the dipstick or it leaks around the rubber seal on the dipstick (which if there were much pressure involved I expect it would). A vent elsewhere in the case would not change this.
 
   / HST oil level #15  
Remember, the sink full of water in my example is fully vented, and the air pocket still gets traped in the cup. The vent doesn't matter in this issue. It is the seal rings on your dip stick that is most likely causing thatlittle air pocket getting trapped in your dip stick tube. They seal so well that it traps air just in the tube, not the whole rear case. Its normal. Some dipsticks seal better then others.

Your trans/hydraulic system on your tractor does have a vent. On my kubota b tractors itwas on the right side, on top of the rear case, just under the seat. It looked like a rubber, black, candy cane top, you know with the little curl at the top. That was the vent, atleast on mine. Yours may be different, but should be located near the same location, either left or right under the seat comming out top of rear case of tractor.
 
   / HST oil level #16  
I see the same thing when I check the fluid on my B7800. Hasn't been a problem.
 
   / HST oil level #17  
So as with my ice cream cone, the best thing to do is DOUBLE DIP .
 
   / HST oil level #18  
namesray.....can't argue with that logic...makes perfect sense to me...thanks
 
   / HST oil level
  • Thread Starter
#19  
Alright your explanations are sinking in now. Agreed oil is not compressible and I get the idea of the tube.
I just went out and check there is a tube in fact the tube is not even in the gear case. There is an exposed steel tube (for the dip stick) that connects with a rubber tube (hose) on the outside of the case. The rubber tube (hose) is hard to see. Yes if the oil drained out during operation on un-level ground it would not fill the dip stick tube if the dipstick seals correctly. The dip stick has an o-ring and it will seal. I thought the dip stick went directly into the gear case which is why I wondered where the oil went.

Sometimes the simple stuff is not so simple.
Thanks guys you have relived a worry.
 
   / HST oil level #20  
i didn't get any owners manual with my tractor and only had it a couple days I just haven't tracked one down yet but what position do you have ur cylinders in for the check. B21 TLB. Sorry not trying to hijack. Thx
 

Marketplace Items

2014 FREIGHTLINER 108SD CONCRETE MIXER TRUCK (A59823)
2014 FREIGHTLINER...
TANK MANIFOLD (A55745)
TANK MANIFOLD (A55745)
2020 MACK GRANITE (A58214)
2020 MACK GRANITE...
2018 Ford Escape AWD SUV (A59231)
2018 Ford Escape...
208735 (A60430)
208735 (A60430)
2019 Allmand Night-Lite V-Series 7 kW S/A Towable Light Tower (A55973)
2019 Allmand...
 
Top