BX25 hydrolic noise.

[sxs191]

My BX25 has 91 hours on it. When the hydrolics get under load they make a high pitch screeching sound. (whether it be for the 3PH or bucket) It just started, not sure what it could be. Stupid quiestion # 1. Is the same hydrolic fluid used for the tranny the same for the hydrolic lines? Thanks, Scott

 

[oldnslo]

My BX25 has 91 hours on it. When the hydrolics get under load they make a high pitch screeching sound. (whether it be for the 3PH or bucket) It just started, not sure what it could be. Stupid quiestion # 1. Is the same hydrolic fluid used for the tranny the same for the hydrolic lines? Thanks, Scott

#1 yes the fluid is the same for the tranny and hydraulic system.

Does the noise change when the tranny gets warm Vs cold at start-up? If yes have you changed the fluid and filter, and cleaned the inlet screen? Was the 50 hour service performed? If not the inlet screen may be partially plugged and is restricting the flow of oil to your pump which will cause it to self destruct.


How much load? Are you trying to lift close to rated load of the tractor? If yes the system relief may be opening.

Roy

 

[sxs191]

Roy,
The noise does seam to change as the tranny warms up. I did perform the 50 maintenance and changed the oil/filter and cleaned the screen. I double checked the hydro fluid last night. (it was a little past full so I took some out) I will pull the screen tomorrow and clean it again. It primarly makes the noise when the 3PH and bucket hit their full range of motion. Eeek! I don't like that 'self destuct' term
Thanks

 

[638]

That's a normal sound when the limt of travel is reached. The pressure relief valve is unloading the system. You need not to have removed any of the over filled hydralic oil. A little over won't hurt a thing.

 

[sxs191]

Thx 638. It sure is one annoying noise everytime I curl the bucket all the way or raise the 3PH to max height.

 

[oldnslo]

The noise is to let you know you are at max presssure limit. Some valves are a lot noisier than others.

The self destruct mode is if the pump is starving (cavitating) for oil. From your description this is NOT the problem so sorry if I alarmed you.

Roy

 

[sxs191]

Thanks. The SCUT doesn't seam to have lost any of it's lifting cababilities so I will chalk it up as a loud @$$ valve. It just started making the noise within the last week though, that's what got me conserned. (maybe it dreds the heat as much as I do)

 

[CHDinCT]

When you did the 50 hour service, did you change the hydrostatic fluid and if so, what did you use? At the risk of starting a debate on OEM vs generic HST fluids, there have been reports of more HST noise when using fluid other than the Kubota SUDT or UDT. Just a thought.

I agree that what you are hearing is the relief valve openning but if it's noticeably louder than it use to be, maybe it's the type of fluid you used for the 50 hour service.

 

[KubieTwo]

When you did the 50 hour service, did you change the hydrostatic fluid and if so, what did you use? At the risk of starting a debate on OEM vs generic HST fluids, there have been reports of more HST noise when using fluid other than the Kubota SUDT or UDT. Just a thought.

I agree that what you are hearing is the relief valve opening but if it's noticeably louder than it use to be, maybe it's the type of fluid you used for the 50 hour service.

As far as the fluid, my tractors and my RTV make less noise with SUDT than UDT, but under load hydraulic pumps do make noise. I have a Woods bh with an external pump and even before it hits relief pressure it does sing. I like the sound. HST pumps and other hydraulic pumps whine under load, and in most cases this is no cause for alarm. They make even more noise when the relief valve opens. It is possible that he just started hitting the max ranges of the curl and 3ph.

 

[Newfiestang50]

My BX 25 just started doing the same thing, I never heard it before until I used the 3pt hitch for the first time, my BX currently has 160hrs and the 50hr service was done at 50hrs. It does not do it when using the BH. My personal opinion in my case is that when I am using the 3pt hitch its for pulling a box scraper and this implement can tax the BX transmission a little more thus causing the fluid to get pretty hot.

I have however also heard this on one ocassion yesterday when using the FEL pushing some dirt for an extended period of time. I knew I was pushing the BX a little hard and sure enough the squealing started again when raising the FEL while pushing. I have never heard it while operating the BH. I guess the BH just doesn't get the oil as hot.

Just my opinion.