Broken hydraulic Cylinder

[countrybumpkin]

I broke a hydraulic cylinder on my backhoe yesterday, digging out stumps. I couldn't believe the hoe had that much force to break the thing. Anyone know a good place to buy good cylinders for a reasonable price? The dealer is out of the question, they want 1300.00 for it. The parts guy gave me the part number and size; it's a 3x24 with 1 1/8 pins.

Anyelse done this?

Also should I buy a 3000 psi or 2500 psi cylinder, not sure what the hoe runs? Aslo Can I use a Tie rod type or does it need to be a welded type? Thanks

 

[JerryG]

A good hydraulic shop can replace the rod.

 

[countrybumpkin]

Guess I should have said that when it snaped it slammed the tube up againts the hoe and bent the tube too. so the only thing that is any good would be the divider block inside the cylinder.

 

[MadReferee]

A 3" x 24" welded cylinder with 1" pin holes, 3000 psi, Chief brand (made by Bailley) goes for about $237 from Surplus Center. A Prince would be similarly priced.

Are you sure the pin hole is 1-1/8"? I could find no listing for that size in my Bailey catalog, just 1" and 1-1/4". All 3" cylinders from Bailey(Chief) and Prince have 1" pin holes.

If you need something custom then give Bailey a call on monday (800-800-1810). They make Chief cylinders and have all parts on hand and can make up a cylinder with any type of end. Their websire is www.baileynet.com .

 

[Richard]

Just be sure to get a quote BEFORE you authorize the work. I took my dipperstick cylinder in to be rebuilt. (industrial machine)

The bucket cylinder a year prior cost me something like $150 so I figured $200 or perhaps $250 tops for the bigger cylinder. Well was I ever wrong, the bill came to about $650 if I remember correctly /forums/images/graemlins/shocked.gif

I was genuinely flabbergasted and my mouth literally hung open. Long story short, they knocked a bit off the price but I've NEVER been back there since, which kind of bums me out as it was the dealer and they otherwise to this circumstance have ALWAYS been utterly fabulous.

 

[countrybumpkin]

Ya I double checked the pins are 1 1/8. I guess I can use the one inch cylinder with new pins and get bushings for the holes. You think a 3000 psi with 1 inch will be Ok? I was looking at going with a prince brand. looks to be a good quaility.

 

[MadReferee]

What does 3000 psi and the size of the pin have to do with anything? The answer is nothing.

There is no real quality difference betwen Prince and Chief that I have ever seen other than just about 10% in cost difference. Chief and Bailey brand custom cylinders are made in Knoxville while Prince are made in Iowa and South Dakota.

Actually what I would do is replace the new cylinder ends with the existing broken cylinder ends. Any competent hydraulic shop can handle that.

 

[RickB]

Nothing is the wrong answer. The PSI rating of the cylinder should be well above the system relief pressure and even more importantly any circuit relief valve that may be installed in the dipper stick circuit. Selecting a replacement cylinder with the correct pin bores relieves the buyer of the expense and aggravation of changing the pin bosses on a brand new cylinder. Or using undersized pins while bushing down the mounts which is just a bad idea from a strength standpoint.

 

[MadReferee]

I believe your assumptions about bore and pin diameters are wrong. In this case the difference between 1" and 1-1/8" is so small for this application that it makes no significant difference. If it was so critical, then why do cylinder manufacturers have the same pin diameter for cylinders that have 2", 2-1/2", 3" and 3-1/2" bores? You have to go to a 4" bore to get a 1-1/4" pin diameter.

Also, bushing a pin mount is a common occurrence. My local hydraulic shop is always doing that kind of fix when current replacement parts don't match existing applications.

The bottom line for this poster is that he probably exceeded the design specs for this backhoe cylinder and will need to spend the $1300 if he wants an exact replacement cylinder since the pin diameter is non-standard (probably done on purpose). If he wants to use a current aftermarket cylinder and spend less money then some machine work has to be done. The end result will be nearly identical and could possibly be a little better.

 

[RickB]

If my assumptions are half wrong, yours surely are. The maximum operating pressure spec on any hydraulic cylinder needs to be matched to the application, not blown off as insignificant. FWIW the cross section of a 1 1/8" pin is a little over 25% greater than a 1" pin. You can draw your own conclusion on what the difference in shear strength is for a given pin material.