too much for my backhoe?

[simmysam3]

I had cylinder seals replaced(boom) because i thought i had a problem, but that does not seem to be it.

I am exceeding my backhoe spec by of max 20" bucket with a 24", and when fully extended the boom cannot lift a full heaped bucket of soft, but wet sand.

I cannot imagine it not being able to lift the weight, but an extended lever like that extended to maximum reach - is it possible its simply too much weight?

its a small bradco 6.5' backhoe.

thoughts?

 

[BungeeII]

My little Taylor-Way couldn't do it either. With it's little 12" bucket I have to bring some big loads in a bit before I can lift it.

 

[banjodunn]

I think you will find that it is just too much for it to lift unless your relief pressure is not up to spec but i think it is just too much weight

 

[Reg]

If you are saying that the biggest bucket spec'd for this hoe is 20" and you have a 24" bucket on it, but expect it to fully extend that when full of heavy wet mud... I think you should be disappointed.

B'leeve it or not, manufacturers actually DO the arithmetic/engineering/testing, they do KNOW what it will do.
Sure, you can sometimes exceed one dimension if you are willing to accept a limitation on another dimension, maybe that is what you are seeing.

BTW, a 24" bucket isn't just 20% heavier than a 20" bucket.
If everything is in proportion it will have 1.2 x 1.2 the surface area in the sheet metal area.
It will be deeper and taller as well as wider, i.e. it could hold as much as 1.2^3 weight of material.
Both these factors will affect the distance to which that weight can be extended.
If you start beefing things up you run up against other limitations, such as loads on pivots and the stability of a tractor who's size/weight the particular hoe was chosen for.
Swinging too much weight around that far out could spoil your whole day (-:

 

[kthompson]

Bet if you had that bucket full of wet sand weighed it would surprise you how much it weighs.

Have a 5 ton excavator with a 20" bucket and a full load of wet dirt will often pile higher but I can really tell a weight difference at full extension. My bucket is not at it's full width suggestion either.

 

[john_bud]

I had cylinder seals replaced(boom) because i thought i had a problem, but that does not seem to be it.

I am exceeding my backhoe spec by of max 20" bucket with a 24", and when fully extended the boom cannot lift a full heaped bucket of soft, but wet sand.

I cannot imagine it not being able to lift the weight, but an extended lever like that extended to maximum reach - is it possible its simply too much weight?

its a small bradco 6.5' backhoe.

thoughts?

Buy a 0-3000 psi gauge and see if they hydraulic relief if letting go at spec or low. They are very very very often sold at a lower pressure to keep you from breaking stuff. Especially while under warranty. If you get my drift....

Probably should be at 2500 psi, but your owners manual should tell you exactly. Adjustments are probably by adding a washer to the relief spring or by turning a screw to tighten it down. Pretty easy, about a 2 on the 1-10 difficulty scale. BUT, you have to have a gauge to tell what you are doing!!

What is the volume of the 20" and 24" buckets? Some wider buckets are quite shallow and will hold less. Then again some are wide and deep! And is it heaped or not?

If you really want to be able to lift the load, you can put on a larger diameter cylinder. Cost will be about 300 bucks or less.

jb

 

[Airic]

I can't see how it would not lift it when the backhoe is extended. I have a 15" bucket and it is only spec'd for 12". If it is too heavy it will lift the front before the cyliner stops moving.

 

[EddieWalker]

The problem is probably how much preasure and volume your hydraulic pump puts out. They only put them in so big, and the smaller the tractor, the smaller the pump. The big difference between a commercial backhoe and a farm tractor of the same horsepower is the hydraulic pumps on the commercial tractors are much, much larger. Since they are not build for pullling anything or running a PTO, they can focus on the hydraulics. In a farm tractor, hydraulics are not the priority, so the focus is on the PTO and power to pull stuff.

My full sized, 555E backhoe has a 24 inch bucket on it. You are trying to use a similar sized bucket on your smaller tractor as I am, but without the hydraulics to support it.

It sounds like you are trying to lift way more weight then the tractor is capable of handling. I would be concerned about excessive wear and tear from exceeding the limits of your hydraulic system. You might be damaging your pins and bushing from the extra weight too.

Either buy a smaller bucket or a bigger tractor, everything has it's limits and pushing beyond those limits is never a good idea for the long term life of that equipment.

Good luck,
Eddie

 

[LBrown59]

I had cylinder seals replaced(boom) because i thought i had a problem, but that does not seem to be it.

I am exceeding my backhoe spec by of max 20" bucket with a 24", and when fully extended the boom cannot lift a full heaped bucket of soft, but wet sand.

I cannot imagine it not being able to lift the weight, but an extended lever like that extended to maximum reach - is it possible its simply too much weight?

its a small bradco 6.5' backhoe.

thoughts?

I can as you're exceeding the specs.

 

[Reg]

Buy a 0-3000 psi gauge and see if they hydraulic relief if letting go at spec or low. They are very very very often sold at a lower pressure to keep you from breaking stuff. Especially while under warranty. If you get my drift....

Probably should be at 2500 psi, but your owners manual should tell you exactly. Adjustments are probably by adding a washer to the relief spring or by turning a screw to tighten it down. Pretty easy, about a 2 on the 1-10 difficulty scale. BUT, you have to have a gauge to tell what you are doing!!

What is the volume of the 20" and 24" buckets? Some wider buckets are quite shallow and will hold less. Then again some are wide and deep! And is it heaped or not?

If you really want to be able to lift the load, you can put on a larger diameter cylinder. Cost will be about 300 bucks or less.

jb

Bigger cylinders just leads to overloading elsewhere, including but not limited to the stability of the tractor.
At some point too much weight extended too far on too small of a tractor becomes a SERIOUS stability issue.
What next, longer stabilizer arms ?
Fatter cylinders all round ?
He is already OVER SPEC on this, single point beef up engineering won't solve the underlying problem.

 

[RWolf]

Sounds like it's time for a bigger tractor/backhoe

 

[dirtworksequip]

It's not uncommon for backhoes or even excavators for that matter not to be able to lift a heaped up bucket of wet material with the boom and stick fully extended.

Sincerely, Dirt

 

[AKfish]

Yup, even the big machines won't do some things that we try to make 'em do!

Was playin' around with a friends JD 160 excavator and a 36" clean-out bucket... reached way over to the end of the boom and dipperstick and grabbed a bucket of wet sandy-dirt...

Good thing the bucket was only 12" or so off the ground 'cause the track on the opposite side of the machine was a similar distance in the air...

AKfish

 

[john_bud]

Bigger cylinders just leads to overloading elsewhere, including but not limited to the stability of the tractor.
At some point too much weight extended too far on too small of a tractor becomes a SERIOUS stability issue.
What next, longer stabilizer arms ?
Fatter cylinders all round ?
He is already OVER SPEC on this, single point beef up engineering won't solve the underlying problem.

We don't know the volume of the bucket. That is the spec that counts, not the width alone. You can get a 36" grave bucket that will only hold 4 cuft or a 24" bucket that will hold 10 cuft. Which one stresses a machine more? Once you know the volume they hold, the answer is obvious.

Some times people want to stress out machinery. Maybe he needs to cut a 24" wide trench and wants to do it in 1 pass not 2. We sure don't know from the initial notes he left us. I just gave him the information on the direction and cost to add that stress.

By the way, the underlying problem is that the boom can't lift the load. Solutions possible include:
1) Smaller load - smaller bucket, shallower bucket, lighter bucket
2) Change leverage - move mounting points etc.
3) Increase lifting force - larger cylinder, higher pressure

There may be other issues that solution #3 bring out, but those would be different ancillary problems. Like tipping loads exceeded, structural integrity failures, etc.

Have a nice Thanksgiving holiday.
jb

 

[Reg]

We don't know the volume of the bucket. That is the spec that counts, not the width alone. You can get a 36" grave bucket that will only hold 4 cuft or a 24" bucket that will hold 10 cuft. Which one stresses a machine more? Once you know the volume they hold, the answer is obvious.

Some times people want to stress out machinery. Maybe he needs to cut a 24" wide trench and wants to do it in 1 pass not 2. We sure don't know from the initial notes he left us. I just gave him the information on the direction and cost to add that stress.

By the way, the underlying problem is that the boom can't lift the load. Solutions possible include:
1) Smaller load - smaller bucket, shallower bucket, lighter bucket
2) Change leverage - move mounting points etc.
3) Increase lifting force - larger cylinder, higher pressure

There may be other issues that solution #3 bring out, but those would be different ancillary problems. Like tipping loads exceeded, structural integrity failures, etc.

Have a nice Thanksgiving holiday.
jb

Guess again.
The underlying problem is a lack of understanding that Bradco has done the homework on this.

 

[Brad_Blazer]

A sample calculation - I am totally guessing at the dimensions and weights. A 2" cylinder at 2250psi (7068 lbf) with a centerline passing 9" from the pivot point, an 800lb boom assembly with a center of mass 60" from the pivot point, and a bucket load 96" from the pivot point will have a max payload of 163 lb.

(7068*9-800*60)/96 = 163

Put in the correct numbers and see if it makes sense. Your machine is probably functioning correctly. I think that was the only question.

Brad

 

[AKfish]

Thank the good Lord for engineer's....! Next time my backhoe stalls and goes into bypass; I'm gonna git right off and go plug some numbers in and see if it makes sense!

Just had to say it --- Gawd knows I wouldn't even HAVE a backhoe if it weren't for some "smarty-pants" engineers'.

AKfish

 

[Brad_Blazer]

Just use the calculator before you do this:

I had cylinder seals replaced(boom) because i thought i had a problem, ...

 

[kthompson]

If you want to find out how easy it is to over load a backhoe or any other such machine, just do an internet search on such or you tube. When you are the limits on a machine, there can be the point where it seems a "dime" will make the difference in what it can lift and or be stable. It is much safer not to be able to lift it than to lift it and not be stable. Anytime you are pushing what you are lifting keep that load near the dirt, real near. Can save your life and your machine. Of course the closer you can bring the load in is a plus.

 

[john_bud]

One thing that seems to have been overlooked by some is that the OP has a TYM 330 HST tractor. That machine weighs over 3000 pounds and can take a hoe larger than the one the OP bought. The largest hoe looks to be the BT400 that can go up to a 36" bucket.

The op was not talking about a 6.5' hoe on the typical BX sized machine.