Backhoe Backhoe Bent

[Soundguy]

I think you been lucky. At work we have large excavators.. the big tracked kind.. and I can tell you.. a bad operator can ruin that machine in 15 minutes.

soundguy

 

[mazurrj]

Bernie,

I can only speak for the BH75 since thats what i have, although I would think you can use any tool wrong you are going to get you're self into trouble.

On my hoe and others I've talked to you can bend the rods on cylinders if you use the wrong technique. Some call it design flaws, some call it bad technique, whatever, bottom line is you end up with bent rod. After bending a few and seeing others do the same you sort of try not to do the same thing that causes the problem. On my hoe if you are close up to an object like a stump or rock, and if you clurl the bucket trying to break it free, then try and pull up with the not sure what cylinder you call it but the biggest one, the dipper rod will bend. It may take a while but if you tug on it and hear the relief valve, quit, and try another position if its not breaking loose. Maybe its common sensce to others not to do some these moves, but some of us new to this and learn from experience.
I'm sure each model hoe has a little different weakness that is if you want to call it that.
All i'm trying to say is if you are working on something big that is near the limits of you machine, you need to be a little more careful in how you handle the job. Same thing if you have full size hoe, if you're doing something near limits , techniquic becomes more important.

Bob

 

[john_bud]

Don't forget the balancing act between the cylinder so strong it won't bend and the cylinder so strong it breaks structural parts of the hoe.

At some point the "other" part breaks....


jb

 

[Berniep]

Mazurrj:

Maybe because the limits of my machine are so low that it can be built to withstand it. But I have done exactly as you described many time while breaking roots and have notice no I'll effects. Glad I read this though in case I am ever on a larger machine. Heck even on mine I will probably not do it again because now that I know about it,it is sure to happen.

 

[Taiser]

I'm wondering about some kind of defect? Maybe like a relief valve not opening when it is suppose too? I have also put my BH through heck and never had a problem, like pulling HUGE stumps out, rocks, etc. In some cases I've heard scarry groans from the tractor but then the boom hydraulic just stops working until I ease up. If it was that easy to bend I would have bent mine a LONNNNNGGGGG time ago!

 

[mazurrj]

?? I had it to the dealer both times that it bent and they said they checked relief valves. the second time when the dealer brought it back the saleman went out with me and we dug up a stump together. this is when he explained some do's and don'ts to me. I wish it was a relief valve problem, paraniod when i'm digging stumps.

 

[rcrcomputing]

?? I had it to the dealer both times that it bent and they said they checked relief valves. the second time when the dealer brought it back the saleman went out with me and we dug up a stump together. this is when he explained some do's and don'ts to me. I wish it was a relief valve problem, paraniod when i'm digging stumps.

If you are simply digging a stump, I'd say the backhoe mfg simply sucks if it breaks. IMHO

If, OTOH, you are picking it up with a chain, or driving forward etc. That's a different story. But simply stressing the hoe to it's limits digging, curling etc. should NOT break a hoe.

 

[timalabim]

Here's a link to my bent BH post w/pics on page 3
http://www.tractorbynet.com/forums/kubota-owning-operating/121328-bx24-bent-bucket-curl-piston.html

 

[dfkrug]

I'm wondering about some kind of defect? Maybe like a relief valve not opening when it is suppose too? I have also put my BH through heck and never had a problem, like pulling HUGE stumps out, rocks, etc. In some cases I've heard scarry groans from the tractor but then the boom hydraulic just stops working until I ease up. If it was that easy to bend I would have bent mine a LONNNNNGGGGG time ago!

Unless you use a PTO pump, it is not a relief valve problem. When using
the tractor's hydraulics, you have 2 RVs in parallel protecting your hoe,
one on the tractor, one on the hoe valve. They should be set at about
the same pressure, unless you have a crappy hoe. Once the work port on
the valve is closed, the cylinder circuit is not protected from over-pressure
unless there is a shock RV on that work port. The shock RVs are used to
protect against sudden spikes in pressure as caused by the momentum of
part of the hoe when a valve is suddenly closed. Not all work ports have
shock RVs. PTO pump systems depend on the hoe valve RV for protection.

A particular cylinder can experience considerably more force than that
supplied by the hyd system. If you operate your dipper to relief, putting
say 2000 lb of force on your bkt teeth, then curl the bkt, you can easily
double the pressure inside your dipper cylinder. That usually won't hurt
anything as long as your dipper cyl experiences only small side forces. With
that kind of total force on the dipper cyl, the cylinder needs to be almost
perfectly straight at full extension. If the cross-tubes or pins are even
slightly out of alignment, side forces are created. Side forces may increase
to a point of buckling. So it comes down to how well-made is your cylinder
and how accurately welded are your bushings and cross-tubes? This
assumes, of course, that you have not allowed any foreign objects to cause
any cylinder side forces.

 

[MAG]

After reading all these posts and talking with a few "experts" I think operator "error" is the cause of my bent hoe. I was trying to give little jerks to the bucket. These little jerks were hammering the hydraulic system. Bad move, from now on if the backhoe or any other hydraulic system won't do the job I'll quit and find another less expensive way!