BH70 Valve noise

[KickstandDan]

Hello, first of all thanks for offering such an informative forum.
I have been a long time observer but find myself in a situation seeking an unbiased opinion or two.
I have a 2017 Kubota B2601 with a BH70 and FEL. It has 28.9 hours and seems to perform flawlessly except for an exceptionally loud hydraulic squeal when the BH bucket is curled and is under load. It's most noticed scooping heavy dirt or clay. If it's pinned against the mechanical thumb and a stump, it will not make a noise. The noise is solely from the valve body. I have a video to give a better description. It does not make the noise in any other way, shape, or form.
I have searched endlessly using keywords all across the board with no similar findings. If I missed something, my apologies. As far as warranty goes, it's been nothing but "can not duplicate concern".
To be clear, my main question is - is this Normal? This is my first tractor backhoe.
Thank you for your time.
https://youtu.be/3Nk34iWjk4o

 

[100 td]

I don't suppose you have the hydraulic circuit in a WSM to post?
Sounds like a relief bypassing or a valve bypassing, they generally have reliefs on some of the valves separate to the main relief on the tractor but are generally higher pressure overload reliefs.
Is there any noise coming from the main relief valve on the tractor at the same time?
IIRC my B21 has overload reliefs on the boom, swing and dipper, but not the bucket, and they are set ~400 psi higher than the main tractor relief, so when a slab of concrete falls and pushes something while you are operating, the overload relief works to stop something being bent. So if yours is similar, the main tractor relief should work at stroke end. Does either of the stabilizers make any noise at stroke end?
You do say that it makes the noise when scooping heavy dirt or clay, is this prior to the cylinder being at end of stroke?

 

[tempforce]

my bh70 made a hissing noise whenever it was used. after having the valve body seals replaced, due to leakage. and new udt2 fluid... most of the noise is gone... so i'm assuming the noise i had, was in the valve body...

 

[KickstandDan]

Unfortunately I do not a hydraulic diagram of the WSM to reference. There is no real "noise trouble shooting" section I can find for the BH70 either. I was hoping to find it so I could check for a large heat differential and perhaps diagnose it myself more easily. There is no noise at all from the main relief on the tractor. The noise only occurs when the bucket is curled, zero noise when the stabilizers are used. It occurs during the stroke prior to the cylinder being at the end of the stroke. I have straight edged the piston to make sure it wasn't bent out of precaution, but the noise clearly comes from the body itself. Is this abnormal pressure relief noise or is it considered normal in the field?
Tempforce; If you don't mind me asking, were the valve seals replaced under warranty through kubota or did you have them done elsewhere? Do you recall the number of hours you had when you first got noises?
Thank you both for your responses.

 

[100 td]

So if it's not relieving at the main valve it's possibly bypassing the spool itself. Get your dealer involved again because if it is bypassing the spool (or anywhere) it will probably need replacing.
It's a new machine, get them to sort it.

(A mechanics stethoscope or screwdriver in your ear may help!
I had a look at my hydraulic circuit but it may be different than yours, also it appears your valve body may be one machined block so if one gallery was poorly machined the entire block would need to be changed, but if one spool itself was poor it could be replaced.)

 

[KickstandDan]

So if it's not relieving at the main valve it's possibly bypassing the spool itself. Get your dealer involved again because if it is bypassing the spool (or anywhere) it will probably need replacing.
It's a new machine, get them to sort it.

(A mechanics stethoscope or screwdriver in your ear may help!
I had a look at my hydraulic circuit but it may be different than yours, also it appears your valve body may be one machined block so if one gallery was poorly machined the entire block would need to be changed, but if one spool itself was poor it could be replaced.)

Thanks for the advice, I didn't think this was considered normal noise but don't have the experience to back it up. I don't have what I consider a great dealer network where I am up north, but I'm going to try to have one of the techs or manager observe it in person at my home where it happens quite frequently. I'm not aware of any test sites either dealer near by has for actually digging holes. As I said, everything operates well, but I fear I may have to keep digging until a hard failure occurs before they can duplicate any concern.
I appreciate the help.

 

[tempforce]

my back hoe attachment was out of warranty. had the repairs done at local Kubota shop.

 

[William1]

My BH makes the 'dying moose' sound once in a while on boom swing. If I stop the swing and start it, it goes away, I suspect it some debris in a valve or simply a sticking valve. It has happened since new. I have heard the same sounds from any HST's as well, esp. wen operated under load and slow speeds. I think it is just 'pressure groan' and not a real issue. But I am no hydraulic expert.

 

[KickstandDan]

My BH makes the 'dying moose' sound once in a while on boom swing. If I stop the swing and start it, it goes away, I suspect it some debris in a valve or simply a sticking valve. It has happened since new. I have heard the same sounds from any HST's as well, esp. wen operated under load and slow speeds. I think it is just 'pressure groan' and not a real issue. But I am no hydraulic expert.

That's great to know. I've certainly noticed noises from the BH since day one, but this one in particular just seems to get worse. I've learned over the years that just because it's new, doesn't mean it's good. Therefore I cant help but wonder when the $7k+ BH attachment makes noises similar to my '55 International.
I can't get an answer if it's under warranty from my selling dealer since it "could be from abuse" so I may go have to rack up some hours this weekend and see what (if anything) lets loose!