Hydraulic oil level after oil and filter change?

[Complete Turf Care]

Today, both my tractors were due for a hydraulic oil change. I have a Kubota L5740 and a Kubota L6060. Both are HST and use the same filters and quantity of oil.

The owner's manual says the capacity of hydraulic oil is 11.9 gallons on both.

We drained the oil from the 3 drain plugs, replaced both filters (hydraulic and transmission) then added 10 gallons. After adding the 10 gallons, the oil level was above the 'full' marking on the dipstick. We then ran the tractors for several minutes operating all the hydraulics and driving around the yard for a few minutes.

Then we checked the oil level again, and it was right at the full mark.

My concern is that we added 10 gallons, when the manual says the capacity is 11.9 gallons. Am I doing something wrong? Is all of the oil not draining out? Why can't I add the full 11.9 gallons?

 

[DEWFPO]

You can almost never get ALL the fluid out. All the hoses have fluid in them, there's air lock's, etc... The capacity listed in the manual is typically for a 'bone dry' system. They really should put the 'drain & refill' amount in the manual. Some do, some don't.

DEWFPO

 

[Complete Turf Care]

You can almost never get ALL the fluid out. All the hoses have fluid in them, there's air lock's, etc... The capacity listed in the manual is typically for a 'bone dry' system. They really should put the 'drain & refill' amount in the manual. Some do, some don't.

DEWFPO

That makes sense. I'll just make a note in my maintenance records to buy only 10 gallons for the next change.

 

[sixdogs]

You ever know what they will take. Do it on a red hot day with a red hot engine, let it drain longer and you can get more in. A little colder and quicker and not as much. Whatever you can get in, without overfilling, is the right amount. Works for me.

 

[RjCorazza]

The way I deal with HST oil changes and my OCD, is to measure the fluid I get out
My ZD mowers take the OEM specified amount of HST fluid when changed, the tractors not so much. I would recommend checking the level over the next few uses to be certain the level is correct.

 

[oosik]

My 2009 Kubota M6040 is just the opposite. The Op Manual says 59.2 quarts or 14.8 gallons. For a complete hydraulic oil/filter change takes 16.3 gallons. Either I get better "drain down" than was expected or the initial engineering calculations were off.

The nice thing - 16 gallons gets the oil mark "on the dipstick". Then its just run - let it set for a while - top it off.

 

[Texasmark]

Some equipment owners manuals state new fill quantity, and refill quantity for the very fact, as others have mentioned, all the oil doesn't drain out.

Something I have discovered with some hyd. system dipsticks, occasionally, is that if I just pull the stick and look at it, after it hasn't been pulled for 20 operating hours (for a number) no oil shows up on the stick. First inclination is to run grab the fluid and top her off.

Before you do that, wipe the stick with a rag/towel, stick it back in and check the level again. Have yet to find it lower than the operating range! May save you a lot of trouble and expense in over filling.

 

[skipperbrown]

I have learned that dipsticks are sometimes not calibrated accurately, especially the really long ones (like 3' long). Some truck dealers will drain the crankcase, put in oil to manufacturers specifications and re-mark the dipstick to the actual level.

 

[Texasmark]

I have learned that dipsticks are sometimes not calibrated accurately, especially the really long ones (like 3' long). Some truck dealers will drain the crankcase, put in oil to manufacturers specifications and re-mark the dipstick to the actual level.

That's contrary to what I read in service manuals. Every one that I ever read on the subject, and I've had many types of engines over the years, including a 11 gallon oil system on an 800 cu. in., 400 HP, Big Cam Cummins diesel, is that the dipstick is calibrated for the correct oil height in the engine on level ground, not the refill quantity of oil which varies for several reasons upon refilling. That's why instructions are given to fill it to the full mark, run the engine to circulate the oil, turn it off, let it sit for a few minutes, re-read the dipstick and top off accordingly.

In fact my Branson manuals list 2 oil quantities, one for initial fill (factory fill) and a second, lesser quantity, for refilling and with or without filter is also included in the numbers.

I'd cease to do business with any service facility that remarked my dipsticks!