Hissing coming from loader

[Bdm300]

I was out using the loader today on my bx 2670, and whenever I would lower the loader it would make a hissing sound near the right lift cylinder. There is no leak anywhere and believe its done it since new. It only happens when lowering. Almost sounds like there is an obstruction of flow somewhere maybe making a loud hissing sound. Is this normal or do I have an issue?

Thanks, Bryan

 

[Rocky Hoffler]

Hissing noise usually comes when a relief valve is being cracked open. maybe weight of loader going down is opening a valve would have to have hyd. schematic to tell and this could be normal

 

[Bdm300]

I wonder where I could get a schematic. I'll have to do some checking on that because I don't have an owners manual for the loader. Thanks

 

[s219]

Depends on your definition of hissing. All the loaders I have owned make a "psssst" sound when lowered, and how much depends on how you are working the valve lever. If no leaks, it's probably normal.

What about putting into float to lower (not too high off ground though), what noise does that make?

 

[kuboman]

I think you are hearing the oil passing through the valve as you lower the loader. Very normal sound.

 

[Bdm300]

Hopefully it is normal but just seems louder than it should. I'm gonna "play" a little more today and try different things and maybe I can better explain.

 

[Bdm300]

Well strangely enough, it isn't making the hissing noise today. I guess I'll keep working it and see if it happens again. Thanks

 

[k0ua]

The loader on the Kubota L3400 I had would make a loud hissing sound if I shoved the loader valve all the way forward into float as the loader arms came down. If I did not go past the float detent I did not notice any hissing if I just powered down the arms. In the float setting the weight of the arms and the bucket are pulled down by gravity, but they come down in a controlled manner.. Not so my Kioti, If the bucket is up high and I shove he control into float, there is no hiss, but the arms drop like a rock. BANG! on the ground. The Kubota evidently had a restriction to allow the arms to come down slowly in float. If you listen close on this old video I made you can hear it at the 3 second mark.
https://www.youtube.com/watch?v=7Wh-Y0d-pfw

 

[Fallon]

My l3200 whistles pretty good when coming down in float. Can't say I've noticed it being that noisy when not in float.

 

[k0ua]

My l3200 whistles pretty good when coming down in float. Can't say I've noticed it being that noisy when not in float.

I just noticed it in float.. I think there must be some restrictor in the float orifice of the spool valve. It is all I could think of. I learned pretty quick not to do that with the Kioti. You need to get the bucket powered down to pretty close to the ground before you shove it into float..

 

[Fallon]

Mine drops fast, but not disturbingly so. I have no qualms about dropping my loader in float from any height. Quite probably a restrictor in there on the float circuit.

 

[tcreeley]

When my hydraulic oil filter needs changing, I hear it using the fel. When I change the filter, everything is quiet. Might check that out,

 

[Fallon]

When my hydraulic oil filter needs changing, I hear it using the fel. When I change the filter, everything is quiet. Might check that out,

It's done that since day one. I've got 130ish hours on it now & it was doing it just after my 50 hour filter change. Pretty sure that's just Kubota thing, & it's only in float when dropping somewhat fast, not when being powered up or down.