What happens if your hydraulic reservoir is overfilled?

BruceWard · Feb 26, 2009

Specifically on a B21. I overfilled it. I am going to drain the extra. But it leaves me wondering what happens if you have too much fluid?

kennyd · Feb 26, 2009

The fluid can/will come out of the vent or fill tube when it expands due to heat.

WaxMan · Feb 26, 2009

I overfilled mine when I changed it , It's easy to do . I drain a little and topped it off slowly to the right level. I would say nothing will happen . But I didn't want to take a chance and have any seals leak.

Just read kennyd post and that makes sense

rbargeron · Feb 26, 2009

Tractor reservoirs usually run somewhere around half full. The gear housing makes a handy storage location for the oil but it's way bigger than needed. Notice your sight glass or dipstick mark and then notice how much higher the top of the housing is. There's a lot of extra capacity. Over-filling has little effect unless it's a huge amount. Even then it probably would only be a nuisance - running out the dipstick hole or something when it heats up. Most owners would never see any effect from an extra quart or two. Engines are more sensitive to oil level. As always, prompt cheerful refund if info is bogus. Dick B

aggiehortguy91 · Feb 26, 2009

rbargeron said:
Tractor reservoirs usually run somewhere around half full. The gear housing makes a handy storage location for the oil but it's way bigger than needed. Notice your sight glass or dipstick mark and then notice how much higher the top of the housing is. There's a lot of extra capacity. Over-filling has little effect unless it's a huge amount. Even then it probably would only be a nuisance - running out the dipstick hole or something when it heats up. Most owners would never see any effect from an extra quart or two. Engines are more sensitive to oil level. As always, prompt cheerful refund if info is bogus. Dick B

I have to agree. I have often slightly overfilled (although not intentionally) the hydraulic oil on many tractors with no ill effect. My BX2200 is usually about 3/8" above full just because SUDT is almost impossible to see on the dipstick.

Keep in mind that I am talking about only slightly overfilled. If you fill 'er up to the top, all bets are off and you need to deal with that by draining back to the proper level.

And I am fully prepared to stand behind rbargeron's guarantee

Rford · Jun 24, 2015

I know this is a very old thread...but I just bought an old Ford 2000 and decided to change the hydro fluid even though the prior owner said he did so two years ago. I opened the "full" plug and drained out 5 gallons---which is the capacity. I then dropped the drain plug and drained out 5 more gallons! Who knows how long it ran that way. The fluid didn't look new. No leaks and the hydraulics work good. Of course, I haven't driven it since the change, so hope I'm not surprised.

DonaldP · Aug 17, 2021

rbargeron said:
Tractor reservoirs usually run somewhere around half full. The gear housing makes a handy storage location for the oil but it's way bigger than needed. Notice your sight glass or dipstick mark and then notice how much higher the top of the housing is. There's a lot of extra capacity. Over-filling has little effect unless it's a huge amount. Even then it probably would only be a nuisance - running out the dipstick hole or something when it heats up. Most owners would never see any effect from an extra quart or two. Engines are more sensitive to oil level. As always, prompt cheerful refund if info is bogus. Dick B

I’d like my refund please!!!!

rbargeron · Aug 17, 2021

DonaldP said:
I’d like my refund please!!!!

Hi DonaldP - In all the times I've made that offer you are the first to take me up on it ! Please let me know which info was bogus - and 12 years later "prompt" isn't possible -but cheerful is

LouNY · Aug 17, 2021

We routinely over fill on purpose, depending on the tractor from a couple of gallons to 5-6 over.
All of are ground is hilly and steep we prefer to be a tad over full then run a chance of anything sucking air while working hard on a slope.
My Oliver 1550 had to be a qt. over full on oil when working my driveway as if not the oil pressure would bounce when it sucked a little bit of air.