BX24 backhoe question - is it broke?

[fishpick]

So - simple question... BX24 - about 25 hrs on it... love it... I've got enough experience with the BH to know that it's not super fast when engaging both levers to do boom/dipperstick or swing/bucket work - but it's fast enough... so here's the issue tonight that has me concerned something is wrong with my BH.

Tonight I'm outside digging a trench across the gravel driveway with the BH and all was going fine - then I tried to extend the bucket at the same time I pulled back on the boom lever to lift the boom... bucket extended and then the boom moved... It seems if I move the bucket and the boom raise/lower at the same time - the bucket goes fine - boom will not raise (lowers, but the manner looks like gravity more than hyro).

So - question is - should the boom be able to raise at the same time the bucket is curling or extending? Dipper stick does, boom will swing... just will not raise with the bucket moving - stop moving the bucket the boom snaps right up fine. Sounds bad to me.

Also relevant - I DID move all the hydro cylinders on the BH and the loader through ALL ranges of motion a couple of times to ensure that there wasn't air anywhere in the system.

 

[jeffmazz]

I believe what you are describing is normal operation. The control functions on these little tractors is somewhat limited due to pump capacity. Certain movements can't be performed at the same time. My BX22 does the same thing.

 

[Berniep]

Yeah there are certain combinations that my bx23 wont do also. It can get a little frustrating but then I think about how long it would take using a shovel and I get over it.

 

[guyrj33]

I have the same issue with my woods 7500 BH driven from the hydraulics on my B7800. It is a real pain, and slows down work.

 

[radair]

Same deal with my 23. Once you get to 50 hours and can jack up the rpms the backhoe is quite a bit quicker.

 

[LarryRB]

full movement backhoe's or commercial backhoe's have two (dedicated) pumps for the hoe. You only have one pump.. You will never get multiple movements with one pump...

 

[rdsaustintx]

Same with my BX23. Proportioning valves give priority to the curl cylinder (where it's needed most). You get used to it.

Russell in Texas

 

[dfkrug]

An open center system with multiple valves will always send oil
along the path of least back-pressure. If you open your boom
lift valve at the same time as opening your dipper stick lift
valve, for example, the dipper will rise first. Normal, since
less pressure is need to raise the dipstick.

This same phenomenon is noticable if your tractor shares a
hyd pump between power steering and implements, as some
budget tractors do. Dumping your loader bkt while steering results
in suddenly sluggish steering.

 

[Jay4200]

So - question is - should the boom be able to raise at the same time the bucket is curling or extending? Dipper stick does, boom will swing... just will not raise with the bucket moving - stop moving the bucket the boom snaps right up fine. Sounds bad to me.

Perfectly normal. When you open two valves at the same time, only the one with the least resistance will move. Try the same thing, but run the bucket into the ground - you'll see the boom start to swing the instant the bucket hits. Moving two axis at once is where the operator's skill comes in - you have to "feather" the controls so you can steer pressure to both pieces at once.

Remember how you get to Carnage Hall!

Jay

 

[fishpick]

Thanks - since I'm impatient - as I was waiting for responses - I called the dealer... he didn't have a BX24 on the lot - so he went to a guys house who has one they sold that's close to the dealer and asked to test it out... The dealer also called Kubota to confirm...

The answer is - everyone here is right! The boom weighs more than the resistance offers by the bucket swing... and the comment about hit the ground - EXACTLY correct... that makes the boom move, since the bucket resistance is greater than the weight of the boom.

Thanks!

Note: my dealer (Alexander Equipment) is AWESOME!