Oil & Fuel Hot oil expansion

[sandyc]

Used my BX 2380 for a few hours yesterday plowing and blowing snow. After that I checked the oil level in preparation for Monday’s storm.(I use AMSOIL after 50 hour change). The level was about a quarter of an inch above the full mark. Thoughts of rings being bad
Went through my brain, cussed a bit and went into the house.
Today I went out to the barn and figured I draw off the excess. Just for grins, I checked the level again and it was at the full mark. I Googled the expansion of hot oil both synthetic and Dino and found that synthetic would expand when hot.
Anyone else had that happen?

 

[Gator6x4]

Does Engine Oil Expand When Hot? Informative Guide | Vehicle Fixing

If you're wondering, does engine oil expand when hot? This article has answered the question, does oil expand with temperature? Read till end.

vehiclefixing.com

 

[5030]

Both mine do that all the time. I ignore it. Keeps in mind that your dipstick is just an approximation anyway.

 

[redman135]

This is normal.
On large earthworks machinery the dipstick will read "normal"(cold) on 1 side and the other will read "run"(hot),
and the levels will be different.

 

[Roadworthy]

I check my oil before I start - engine cold. I've never had reason to check it hot.. I check it again the next morning and it's fine. The only time I've noted an increase in cold oil level was connected to a similar lowering of my hydraulic fluid level - bypassing the pump shaft seal.

 

[oosik]

Many years ago - checked the hydraulic oil level on the tractor - prior to starting. It was down half a quart. I added until it was at the full mark. Half way down my mile long driveway - a rather loud "POP". Fortunately the fill plug was plastic - it was bright yellow - I found it lying there in the snow. There was a puddle of hydraulic oil on the driveway. Live and learn........

 

[90cummins]

I have a Ford 1720 thats always parked inside after snow blowing & to open up floor space I put the loader up & set it down on a support.
I went in the garage next day & found loader still up & the 2x4 on the floor.
As the captive oil in the hydraulics warmed up it expanded & lifted the loader up. Since then after setting loader down on the support & shutting down I relieve all pressure & put the lever in float to prevent this from happening again & possibly damaging my vehicles.
Yes oil does expand measurably cold to hot.
I never would have thought that such a small volume could expand & lift the loader as the oil warmed.
90cummins

 

[old and tired]

Not sure if your BX has something like my tractor (only smaller values)...

My L2800 HST uses 6.2 gallon of hydraulic fluid but it has a 9 gallon holding "tank" that has at least 3 gallons of head space (someone over-filled theirs to the top, then measured what he drained out).

I had an oil hose to the cooler let loose and I lost 2.5 gallons but was able to drive it back to the house, no problem. I measured what it took to get it back to the sight glass. So there was still, 3.7 gallons in the "tank".

I then added an extra gallon to make sure it stays topped off. Reason for that is because early versions of my standard "L" had loud ratcheting CAMS (if the pto implement over-ran the pto drive-line). If you complained enough, you would get the "Dip Stick" treatment.

That is to say that the sight glass is removed and replaced with a dip-stick that was a couple inches taller (I have only known one guy that had this done, he drained the hydraulic oil and was way over the "6.2 gallon mark" by 1.5 gallons. He asked on TBN; what was up with that...

The new level of oil, submerged the PTO CAMS under oil making them quieter. Still leaves 2 gallons of head space for expansion. (This "fix" came from [AFFILIATE=1, nofollow=true, newwindow=true, title="Kubota"]Kubota[/AFFILIATE] main office/engineers; under a Product Improvement Bulletin).

Bottom line, The sight glass is just a rough reference point on one side of a larger tank.

Your tractor uses just shy of 3 gallons... Work shop manual

https://kubotabooks.com/AutoIndex/index.php?dir=Tractor%20Owners%20Manuals/&file=BX1880%2CBX2380%2CBX2680%20Tractor%20Mower.%20WSM.pdf

 

[5030]

In my view, oil capacity is like tires. The warmer they get, the more pressure they show. Why you always check the pressure cold and same applies to fluid levels.

 

[grsthegreat]

My rear mount hydraulic oil tank for front snowblower has glass level indicator. Its always quite above normal after a few hours moving snow. But level the next morning. Normal.