BX25-D Bucket Curl Cylinder broke.

[Lil Foot]

The failure mode of the one BX cylinder I have seen was not a broken piston, but rather all the threads ripped off the piston end of the ram. Cost of the ram from Kubota was higher than the price of a new cylinder, and making a new ram from scratch was even higher, according to the local hydraulic shop. I was asked to turn the damaged ram down & re-thread to a smaller size, then alter the piston to fit. I was able to convince the owner that if the original failed, a smaller one would not last long. He bit the bullet & bought a new complete cylinder.
Having said that, I think the broken piston failure is much more common.
If I owned one & had this failure, I would probably machine a new piston from a stronger material, like SS. Not sure where that would shift the failure point to, (the threads?) but I'll bet the piston wouldn't break again.

 

[Flienlow]

The failure mode of the one BX cylinder I have seen was not a broken piston, but rather all the threads ripped off the piston end of the ram. Cost of the ram from Kubota was higher than the price of a new cylinder, and making a new ram from scratch was even higher, according to the local hydraulic shop. I was asked to turn the damaged ram down & re-thread to a smaller size, then alter the piston to fit. I was able to convince the owner that if the original failed, a smaller one would not last long. He bit the bullet & bought a new complete cylinder.
Having said that, I think the broken piston failure is much more common.
If I owned one & had this failure, I would probably machine a new piston from a stronger material, like SS. Not sure where that would shift the failure point to, (the threads?) but I'll bet the piston wouldn't break again.

My piston had a "small" break.

here is s a few shots I took during the project.
https://www.youtube.com/watch?v=NJ67gTtyBSw

(and sorry, I cannot film, talk, and think at the same time.)

 

[lugbolt]

Using SS for piston material will wear the bore much faster than aluminum will.

 

[Lil Foot]

Not with proper wear rings. Piston should never touch the bore.