hydro/trans fluid level

[Highbeam]

So I did my second change a little late at 917 hours. Everything went very well and I didn't spill any oil. 7 freaking gallons seems like such a waste. The fluid level in the sump seems to climb as water accumulates.

I've always had this question that should be easily answered.

How do you check the oil level in the trans. There's a dipstick but the instructions aren't clear. Do you check the level with the engine off, cold sump, implements down? Do you check it with the engine running like an auto trans? Hot oil, cold oil, in gear, out of gear?

Overfilling is bad, underfilling is bad. I want to get this right so what is the TBN community's advice?

 

[VictorW]

I check my CK30hst with the engine off, oil cold, and any hyd cylinders extended. I make sure the oil is not below the low level mark on the stick. Actually, I keep it in the middle of the two marks. Any later heated oil and cylinders closed still doesn't put the oil above the high full mark. This way I keep it in the higher range but not overfilled.

 

[MichiganIron]

Level ground is certainly a good idea. We generally fill with the loader bucket on the ground and bucket curled. We then fill to just below the top mark. If there is a backhoe attachment for the tractor, we do the same with the cylinders after they are initially charged.

If the tractor is a hydrostat, make sure you let the tractor idle for about 5 minutes (clutch pedal out on the ck's) before you use the hydro. This assures any trapped air is worked out before loading the transmission. After the 5 minute idle, re-check the fluid level.

 

[Highbeam]

Thanks guys. I'll be checking level with engine cold, not running, and loader on the ground from now on.

I was a little overfilled before the change. These cast iron transmissions pick up moisture and the level goes up over time. Maybe just my climate? I had let some out of a final housing last summer since I noticed the overfill condition then. It came back over the winter. Fluid wasn't particularly cloudy though.

 

[jimmyj]

Very helpful post. Thanks.

 

[IslandTractor]

I have not noticed this with my DK40se but with my CK20 I would get erroneous hydraulic fluid levels if I checked with the engine cold. As I recall there was some sort of vacuum phenomenon that occurred as the engine cooled which must have affected the level (making it appear lower than it was). I found on a couple of occaisons I would check the hydraulic fluid level before starting the engine, note that it was low then add until it showed proper level but then when I actually ran the tractor and things heated up again excess fluid would foam out of the dipstick shaft. When I changed my practice to check the fluid level after I had started the engine, run it for a few minutes, moved the tractor (really I just started it and backed out of the barn) then shut it down and checked I got a reliable correct value.

Maybe that was just my weird experience or maybe it was just related to something about the CK20. In any case, my routine now is to start the tractor back it out of the barn then shut it down and proceed with fluid checks, general inspecton and greasing. Easier to do it outside with better light and it avoids the problems I used to have with the CK20.